Discover how Thermonator helps you solve your calculations quickly.
Thermodynamics is easier with Thermonator. Learn the basic functions and you’ll save yourself countless hours of repetitive calculations.
But you need to understand Thermodynamics to use Thermonator effectively. For example, a scientific calculator calculates trigonometric functions, but you need to understand what a sine function is or the laws of angles to solve trigonometry problems. Thermonator calculates very quickly, but you must perform the calculations correctly. You need to understand what a control volume is or the laws of thermodynamics to apply them correctly. If you don’t know Thermodynamics, your calculations will be incorrect.
Don’t panic. Thermonator includes many explanations and examples to answer the most common questions and help you avoid beginner mistakes.
Thermodynamic values and equations can vary depending on the exercise you’re solving. For example, pressure in bars is not the same as pressure in kilopascals, and the equations used for closed and open thermodynamic systems are not the same. They can even change depending on the textbook or table you’re using.
This means you need to consider the conditions of your exercise to ensure the results are correct. In the following sections, you’ll see how Thermonator helps you define these conditions.
What thermodynamic system do you need to solve? How will you analyze it? What units will you use?
After reading the problem statement, this screen helps you define what you will solve and how you will analyze it, ensuring you use the correct values and equations.
Click the ‘New exercise’ button or open the ‘Settings > New exercise’ menu to access this screen.
Within this screen, the ‘New Exercise’ button clears the current configuration, requiring you to select new options to ensure that no unwanted settings remain from the previous exercise.
By pressing the ‘Examples’ button, the ‘Devices’ menu shows how each thermodynamic device is configured, for example, that a turbine implies an open control volume system. You will also find links to solved exercises that may help you.
Finally, there are the configuration options. These appear together so you can quickly configure them before starting to solve the exercise, although you can also configure each one separately afterward, as we will see in the following sections.
What thermodynamic properties do you need to solve your problem?
It’s best to display only the properties you’ll be using, as it’s harder to concentrate when many numbers appear on the screen due to information overload.
To solve this problem, you can use the ‘Properties’ screen.
The ‘Properties’ screen is accessed via the ‘Settings > Properties’ menu.
This screen displays all the thermodynamic properties calculated by Thermonator. They are divided into four groups:
State properties, which are the values that characterize a thermodynamic state.
Saturation properties, which are the properties of a state at the boundary of a phase change, i.e., saturated liquid or saturated vapor.
Process properties, which are the values that characterize a thermodynamic process.
Cycle properties, which are the efficiencies of the cycle.
Each property has an ‘Information’ button to learn more about it.
Remember that some properties may have different values depending on the textbook or the type of thermodynamic system you are solving. For this reason, some properties are marked with icons to remind you, for example, if they are extensive properties or if their value depends on the reference state. If you have any questions, click on the icons to see more information about each property.
We must be careful when selecting the units for each exercise, since mathematical equations always return a result, but that result is only correct when the units are also correct.
The ‘Settings > Units’ menu opens the screen for selecting the units for your exercise.
The Units screen has two parts. The first part is the ‘Unit Selector,’ where you configure the units that will appear in your exercise.
The second part is a ‘Unit Converter,’ in case you need to quickly convert between units. Simply select the type of unit you want to convert and enter the value you need in the corresponding unit. It will automatically be converted to the other units of that type.
What type of thermodynamic system do you need to solve? What equations will you use to solve it?
The analysis of the thermodynamic system determines the mathematical equations used to calculate the work done by the processes. You must ensure that you use the correct options for your exercise.
Open the menu ‘Settings > System Analysis’ to access this screen.
You must configure three options:
Control System: The thermodynamic devices used in your exercise determine how work is done or consumed; that is, the equation for calculating the system’s work. Choose the control system according to the devices in your exercise. The work will be calculated using the equation for the control system you select. There are two types:
Control Mass (Closed System): The substance is enclosed within the device. The device performs or consumes work due to the change in volume occupied by the substance, that is, W = m ∫ P·dv
Control Volume (Open System): The substance enters and exits the device. The device performs or consumes work due to the change in pressure experienced by the substance, that is, Wvc = m ∫ v·dP
Sign Convention: The sign in the equation of the first law of thermodynamics can change, but its meaning remains the same. Surprising, isn’t it? Select the appropriate option according to the reference material you are using.
Negative Convention: Some books consider the work done by a device to be positive. That is, positive work decreases the energy of the system. Thus, for a closed system, the First Law of Thermodynamics is expressed as ΔU = Q – W
Positive Convention: Some books consider all energy entering a device to be positive. That is, positive work increases the energy of the system. Thus, for a closed system, the First Law of Thermodynamics is expressed as ΔU = Q + W
Unit Analysis: This depends on whether we want to measure a point or continuous action of the system.
Energy Units: We measure a point action of the system. For example, the work done by the expansion of a piston-cylinder, measured in kilojoules.
Power Units: We measure a continuous action per unit of time. For example, the work of a turbine in operation, measured in kilowatts, that is, kilojoules per second.
In Thermodynamics, there are several criteria for defining the energy content of a substance in a given state. For example, the IIR (International Institute of Refrigeration) defines a saturated liquid at 0 °C as having an enthalpy of 200 kJ/kg and an entropy of 1 kJ/(kg·K). Meanwhile, the IUPAC (International Union of Pure and Applied Chemistry) defines enthalpy and entropy as zero for a saturated liquid at 1 bar.
For this reason, thermodynamic tables may display different values for energy properties depending on the reference state they use.
This means you must adjust the reference state values for each substance according to your reference sources.
Open the ‘Settings > Reference State’ menu to access this screen.
Adjusting the reference state is very easy. Simply copy the Enthalpy and Entropy values from any state in your table. Once applied, Thermonator will automatically calculate the necessary adjustment so that the values match those in your table.
By pressing the ‘Presets’ button, you can configure the reference state according to different criteria:
When analyzing a series of values, do you prefer to read them in a data table or view them in a graph? Our brains interpret images better, and that’s why Thermonator uses the thermodynamic graph to facilitate the understanding of theoretical concepts.
For example, processes are color-coded to clearly distinguish the type of process based on its heat:
Red represents processes that absorb heat.
Blue represents processes that release heat.
Green represents adiabatic processes, which neither absorb nor release heat.
Let’s look at other examples.
Regarding the First Law of Thermodynamics, we know that the expansion work done by a cylinder-piston system is Wx = m ∫ P·dv. On a Pv diagram, this work is the area under the expansion curve multiplied by the mass of the process.
Graphically, it is easy to deduce that the work will increase as the final volume of the cylinder-piston system increases, since the area under the curve will be larger. We can even approximate the expansion work by counting the squares under the curve and multiplying them by the mass of the process.
Also, since the process is represented in red, we know that the process required heat absorption to carry out the expansion.
Regarding the Second Law of Thermodynamics, to understand the relationship between heat and entropy as Q = m ∫ T·ds, we can represent a Carnot cycle on a Ts graph and deduce that the heat of each process is the area under its curve multiplied by the mass of the process.
Graphically, it is evident that the adiabatic processes, in green, neither generate nor consume heat since, being vertical, they have no area under them. The heat absorbed by the cycle is equal to the area enclosed within the cycle, since the area under the curve of process 4-1, in red, must be reduced by the area under process 2-3, in blue, because it is in the opposite direction. In fact, we can calculate this heat by counting the squares under the curve and multiplying them by the mass of the process.
It is also readily apparent that the heat absorbed by the cycle is proportional to the temperature difference between the hot and cold reservoirs because the area within the cycle increases proportionally to this difference.
In summary, the graph allows us to easily deduce various characteristics of the thermodynamic system, interactions between its properties, undesirable situations, and so on. In other words, it is a great help in understanding the behavior of thermodynamic systems.
Now we will see how to calculate using the graph and adapt its representation to the needs of the exercise.
Using the ‘Substances’ button, select the substance you want to calculate. Substances are classified into three types, each with its own menu, depending on the calculation model they use:
Perfect Gases: This model is the simplest and is widely used in exercises because its calculations are very easy. It uses a constant specific heat and the ideal gas law, P·v = R·T. For this reason, textbooks often treat perfect gases as ideal gases.
Ideal Gases: This model is the most well-known due to its equation of state, P·v = R·T. It differs from the perfect gas law in that here, the specific heat changes with temperature.
Real Substances: These models are the most complex because they calculate the state of a substance, whether it is a liquid or a gas. There are many different models: IAPWS, Benedict-Webb-Rubin, Peng-Robinson, etc. Both the equation of state and the specific heat are complex functions that differ for each substance.
The ‘Search’ menu opens a dialog box with a list where you can select the substance you want to work with. In the text field, you can enter the name, alias, or chemical formula of the substance to facilitate selection.
For each substance, an ‘Information’ button opens a screen with information about that substance. Next to it, the ‘Favorites’ button adds the substance to the main substances menu for quicker access.
The ‘Substance Information’ menu displays a screen with general information about the selected substance. This screen contains:
Main data: Name, chemical formula, molecular mass, and calculation model.
Saturation data, including the enthalpy of vaporization, at the critical point and at normal boiling pressure at 1 atmosphere and 1 bar.
Specific heats and gamma coefficient at different temperatures.
Validity range for calculating the states of this substance.
A thermodynamic state is calculated from two properties. In Thermonator, there are two ways to input these two properties to create a state:
If no state has been created, enter the values of two properties and click the ‘Calculate’ button.
You can also select the ‘New State’ tool and click on the graph. The state will be calculated using the coordinate values on the graph, for example, pressure and volume on a Pv graph, or temperature and entropy on a Ts graph.
To adjust the state properties to the values in your exercise, follow these steps:
Change the value of one property. This will be the first property used in the calculation.
Click on another property. The property you are editing will be the second property. You can change its value or leave it as is.
Click the ‘Calculate’ button. The state will be calculated using the modified property and the property you are editing.
You will see that when you edit properties, the ‘Calculate’ button displays those properties to indicate how the calculation will be performed.
There are special cases, such as modifying the initial or final state of an individual process. In an individual process, it is common to maintain its characteristic property, for example, the pressure in an isobaric process. Therefore, when you modify a property, the Calculator button will also display the characteristic property of the process to quickly calculate the new state using both the property you are modifying and the characteristic property of the process.
When you modify a property, its value appears in red to warn you that it is not the actual value of that property, but rather a value that you are modifying. To restore the original value, press the ‘Restore values’ button located in the upper right corner of the ‘Properties’ panel.
There are situations where we need to rename states according to a specific order, such as when creating complex loops with branches. The ‘States’ button contains the ‘Rename States’ menu to modify the name of each state to the nomenclature used in our exercise.
This same button also contains menus to display each of the states and processes created in the graph. When you select any of them, its property values will be displayed in the ‘Properties’ panel, and the graph scales will automatically adjust accordingly.
Clicking the ‘Graph Type’ button opens a menu with several options. The first options, Zoom and Scales, will be covered in the next section. Then, the different graph types appear, and selecting them changes the graph’s axes. Among them are:
Pv graph: This is very useful for understanding the First Law of Thermodynamics. In this graph, the area under a process represents the expansion work of a closed system, that is, Wx = m ∫ P·dv, while the area to the left of the process represents the technical work of an open system, that is, Wt = m ∫ v·dP.
Ts graph: This is very useful for understanding the Second Law of Thermodynamics. In this graph, the area under a process represents the heat of that process, that is, Q = m ∫ T·ds. For this same reason, processes moving to the right absorb heat and are shown in red, processes moving to the left release heat and are shown in blue, and vertical processes are adiabatic and are shown in green.
Ph and hs graphs: These are widely used, for example, in the analysis of cycles with heat exchangers, because enthalpy represents the energy exchanged by each process.
PT graph: This is used to visualize the saturation line and the different zones or phases of a real substance.
The most common method is to click and drag the horizontal or vertical ruler to move the corresponding scale. You can also tap with two fingers to zoom in or out.
If you want to highlight a specific state or process, the ‘States’ button to the left of the state names allows you to select a state or process to automatically adjust the graph scales accordingly.
Another common action is to zoom in on all calculated states and processes by selecting the ‘Zoom’ option in the ‘Graph Type’ menu.
For more detailed adjustments, the ‘Graph Type’ button contains the ‘Scales’ menu with several submenus:
Help: Displays a reminder of the various ways to adjust the scales.
Range: Opens a dialog box where you can enter the minimum and maximum values for the scale.
P log., T log., v log.: Configure the representation of these properties on a linear or logarithmic scale.
Now that we know how to configure the graph, let’s see how to perform calculations within it.
The ‘Tools’ button offers a menu of actions to add, modify, and delete elements within the graph. These elements are states, processes, and cycles—that is, the components of a thermodynamic system.
When one of these menus is selected, the ‘Tools’ button is renamed to match the menu, indicating the action we want to perform on the graph. Clicking on the graph will execute the action corresponding to the selected menu.
Select the ‘New State’ tool and click on the graph to create a state with the properties of those graph coordinates, for example, pressure and volume on a Pv graph, or temperature and entropy on a Ts graph.
After creating it, the ‘Move’ tool is automatically selected so you can move the state around the graph.
Select the ‘New Process’ tool to display the submenu with the types of processes you can create. The ‘Devices’ menu also appears, containing information on the main characteristics of the most common thermodynamic devices, as well as the ‘Equations’ menu with the equations for all process types.
Once you have selected the process type:
Clicking on the graph creates a process with an initial state at the point where you clicked and a final state where you released the click.
Clicking on a state creates a new process from that state to the point where you released the click.
The ‘Polytropic’ process is a special type of process that can only be calculated with ideal gases.
When creating it, you’ll see that there are no restrictions on the final state. This is because the process can proceed in any direction, depending on its polytropy index.
To calculate its states, on the main screen you can use two state properties, as with any other process, or you can use one state property and the polytropy index.
The ‘Unknown’ process is used when the internal properties of the process are unknown; that is, when we only know the initial and final states. The initial and final states can take any value, so this process can proceed in any direction.
The ‘Unknown’ process is created in purple with a warning icon. The purple color indicates that we don’t know the heat flow within the process, and the warning indicates that we also don’t know its internal properties. To calculate its properties, we must open the ‘Energy Balance’ screen and calculate the balance based on the data from the exercise we are solving.
Select the ‘New Cycle’ tool to open the ‘New Cycle’ screen. When you begin learning Thermodynamics, it’s best to create cycles step by step to understand them and reinforce your learning. Later, it’s better to use this screen to quickly solve problems you’ve already learned and focus your attention on new challenges.
This screen displays the most common Thermodynamics cycles. Clicking on the cycle name displays the cycle’s graph and a link to additional information. The button on the right opens the configuration screen for the selected cycle.
On the new cycle settings screen, you’ll find the cycle’s graph and text fields to enter the values for its properties.
Sometimes your exercise data won’t match these settings. In that case, you can create the cycle with different values and then adjust your exercise data on the main screen.
If we are creating a step-by-step cycle and want a closed cycle, the ‘Close Cycle’ tool is used to join the last state of a cycle with the first state.
Once this tool is selected, we click on the last state of the cycle in the graph and drag it until it overlaps the initial state of the cycle. The last state will be automatically deleted, and its associated process will be joined to the initial state.
The ‘Select’ tool highlights a state or process in yellow and displays its properties in the ‘Properties’ panel. To use it, simply click on the state or process in the graph. Another way to select a state or process is to use the menus in the ‘State’ button, located in the upper left corner of the ‘Properties’ panel.
The ‘Move’ tool is similar. It selects the state or process but also allows you to drag it on the graph to modify its properties.
It is advisable to use the ‘Move’ tool when creating states and processes. After adjusting the exercise data, it is better to use the ‘Select’ tool to avoid accidentally modifying that data.
The ‘Delete’ tool allows you to delete states and processes simply by clicking on them in the graph.
To expedite common actions, when you delete a state with a single process, that process is also deleted. Likewise, when a process is deleted, its initial and final states are also deleted, unless those states also belong to another process.
The ‘Reversing Process’ tool swaps the initial and final states of a process, and vice versa.
When the process belongs to a branch of a cycle, all processes within that branch are reversed. Thus, if it is a basic cycle, the entire cycle will be reversed, making it a very useful tool for quickly analyzing the differences between power and cooling cycles.
The ‘Split Process’ tool divides a process into two processes. This means it creates a new intermediate state and links the initial state to the intermediate state, and the intermediate state to the final state.
This tool is useful, for example, for dividing a turbine process into two parts: the high-pressure turbine and the low-pressure turbine.
The ‘Ladder Processes’ tool streamlines the creation of repetitive processes, such as reheating or recooling processes. Each of these processes consists of an isobaric and an adiabatic process, which are automatically created with this tool.
In general, selecting this tool and clicking on a state linked to two processes inserts two new processes analogous to the existing ones, thus forming a ladder of processes.
In this section, we will look at additional functions that speed up the solution of thermodynamic systems or that are simply commonly used when learning Thermodynamics.
Unit conversions are very common in Thermodynamics and are one of the first skills a student must acquire.
The menu ‘More options > Unit converter’ displays a window to facilitate these conversions. It’s important to remember that, in addition to selecting the working units, the ‘Settings > Units’ menu also contains a unit converter.
The unit converter includes a selector for the type of unit you want to convert and the available units for that unit type.
These units are:
Pressure: Bar, Atmosphere, Technical Atmosphere, Kilopascal, Megapascal, and PSI Absolute.
Temperature: Kelvin, Celsius, Rankine, and Fahrenheit.
Volume: Cubic meter, Liter, Cubic foot, and Gallon (US).
Mass: Mole, Kilomol, Kilogram, Pound, and Pound-mole.
Energy: Joule, Kilojoule, Kilocalorie, Kilowatt-hour, and BTU.
Power: Watt, Kilowatt, Horsepower (international), Horsepower (UK), Btu per second, and Btu per hour.
The value of each unit is modifiable, so changing that value automatically updates the values of the other units to maintain consistency among all displayed units.
A special case is mass units, which require the configuration of the molecular mass of the substance to correctly convert values between all its units.
Interpolation in tables is probably the most repeated (and dreaded) calculation for Thermodynamics students. To address this, Thermonator offers an interpolator that streamlines these calculations and shows the solution step by step so students can quickly check their work and focus their efforts on understanding other Thermodynamics concepts.
The menu ‘More options > Interpolation’ opens the window for interpolating values in thermodynamic tables.
This window performs linear interpolations in one or two dimensions. The one-dimensional option is typically used for interpolating in saturation tables, while the two-dimensional option is used for interpolating in subcooled liquid or superheated vapor tables.
At the top, the ‘Information’ button displays the equations used to calculate each of the interpolation values until the final result is reached.
The ‘Dimensions’ button allows you to select between one-dimensional or two-dimensional linear interpolation.
The ‘Data’ and ‘Calculate’ selectors facilitate data entry. Tables are usually tabulated by pressure and temperature, so at least one of these variables will be part of the data.
For example, let’s say we want to interpolate entropy in two dimensions and we have tables of superheated steam at pressures of 400 and 600 kPa tabulated by temperature. In this case, as shown in the attached image, we would select ‘P’ as the first data point since the tables are at a fixed pressure, and ‘T’ as the second data point since the tables are tabulated at different temperatures. In ‘Calculate’, we would select ‘s’ since this is the variable we want to calculate. With this configuration, the variable names needed for interpolation will be automatically filled in, making it much easier to enter each piece of data.
Once configured, simply enter the necessary data, and the interpolator will automatically calculate the interpolation result.
Finally, a panel at the bottom displays any missing data required for interpolation or any errors. Possible errors include incorrectly entered numbers or data outside the interpolation range (i.e., extrapolations).
Saturation properties are a recurring element in calculations for real substances.
The menu ‘More options > Saturation’ displays a panel where these types of properties can be quickly calculated.
It’s worth noting that saturation properties can also be easily calculated in the main window. Simply display the ‘Vapor Title’ property and calculate a state based on this property and any other property. Values will be saturated liquid when the vapor title is zero, and values will be saturated vapor when the vapor title is equal to one.
The ‘Saturation Properties’ panel first contains a selector to indicate whether you want to enter a saturated liquid or saturated vapor value. Next, another selector indicates the type of property you want to calculate, and you can enter its value in the adjacent text field.
Using this configuration, the corresponding saturation state is calculated, and the property values for the saturated liquid and vapor states automatically appear at the bottom.
It’s worth noting that some substances are zeotropic mixtures and, therefore, do not maintain a constant temperature for a phase change at constant pressure. This variation is called the ‘Slip Temperature’ and is reflected in this panel because the temperature values for saturated liquid and saturated vapor do not coincide.
There are situations where a substance changes its velocity or height, or undergoes dissipation or other energy transfers that alter the results of a basic process model.
In these cases, energy balance is used to determine the process properties.
In Thermonator, it is common to use an ‘Unknown’ process from an initial state to any final state, without restrictions, and then determine the properties of that process in the ‘Energy Balance’ window. However, if the process type is known, you can also create any type of process and determine the changes it has undergone in this same window.
The ‘More options > Energy balance’ menu displays the window for modifying the energy balance of any process.
It is important to remember that the properties and equations in this window will change depending on the configuration you have set for the exercise: Control system, sign convention, etc.
The first step is to select the process whose energy balance we want to modify. Any type of process can be selected, although the ‘Unknown’ type is more common in these cases because it allows for the independent definition of the initial and final states, without any restrictions between them. When the process is selected, its properties appear in the following sections.
The second step is to modify the process properties, including its initial and final states.
In closed systems, we can modify the Internal Energy of the states, and in open systems, the Enthalpy—that is, the property that influences the energy balance. In both cases, a second property is provided, which will remain constant, to allow us to calculate the new state when the Internal Energy or Enthalpy is modified.
Kinetic and potential energies, velocity, and height of the state can also be modified. Modifying the kinetic energy will automatically change the velocity, and vice versa, since they are related. The same applies to potential energy and height.
Finally, Mass, Heat, Work, Expansion or Technical Work, and Dissipative Work can be modified. In the case of the ‘Unknown’ process, these properties are undefined by default, so it is necessary to set them to zero or to the value determined by the exercise being solved.
The third section displays the results of the modifications made.
Partial energy increments that will be added to the total balance: Increase in Internal Energy or Enthalpy, Increase in Potential Energy, and Increase in Kinetic Energy.
Energy balance equation, according to the exercise configuration. If the balance is not satisfied, the ‘Solve’ button allows you to select a property to be automatically adjusted to achieve the balance.
Boundary work equation, according to the exercise configuration. If this equation is not satisfied, the ‘Solve’ button allows you to select a property to be automatically adjusted to achieve this equation.
The bottom panel displays any errors in the configuration of this window, along with an ‘Apply’ button that is enabled when all calculations are correct. By pressing the ‘Apply’ button, the settings made in this window are applied to the original process on the main screen.
Heat exchangers and mixing chambers are very common devices in thermodynamic systems. For this reason, Thermonator offers a dedicated window for quickly calculating the processes involved in the heat exchanger.
The menu ‘More options > Heat exchangers’ displays a list of heat exchangers and mixing chambers.
The list of heat exchangers consists of four types:
Generic Heat Exchanger: A customized heat exchanger with a variable number of inlets, outlets, and substances involved in the energy exchange.
Closed Heat Exchangers: Gas Turbine and Two-Inlet Closed Heat Exchanger.
Open Heat Exchangers (Mixing Chambers): Two-Inlet and Three-Inlet Open Heat Exchangers.
Mixed Heat Exchanger: Three-Inlet.
Clicking on the name of each type displays its schematic, the number of inlets and outlets, and the thermodynamic graph of the processes involved in the exchanger.
Clicking the button to the right of the name opens the window for calculating each heat exchanger.
In the heat exchanger calculation window, the exchanger’s schematic, type, and diagram appear at the top, providing reference during configuration and adjustments.
The first step in the calculation is selecting the heat exchanger processes. All processes within the exchanger must be isobaric, but they must also meet other conditions specific to the selected exchanger. For example, the minimum temperature of an exothermic process can never be lower than the minimum temperature of the endothermic processes. In the case of mixing chambers, the processes must share a common state, which will be the chamber’s outlet state.
The second step is adjusting the exchanger’s energy balance, ensuring that the sum of the enthalpy changes of the processes involved equals zero. To achieve this, the mass and inlet and outlet enthalpies of each process can be modified. The enthalpy changes for each process and the overall energy balance of the exchanger are then automatically calculated.
The third step is to adjust the mass balance of the cycle branches to which the heat exchanger belongs. This section displays all cycle states with branches, allowing you to adjust the masses of branches not yet adjusted in the previous step.
Once the process is complete, the bottom panel contains the ‘Apply’ button to transfer the adjustments to the thermodynamic system on the main screen. If an error occurs, this same panel will display the problem, and the ‘Apply’ button will be disabled to prevent incorrect data from being entered into the system.
We already know how to calculate everything. We’ve learned how to set up our exercise, create the thermodynamic system based on our data, and perform the necessary calculations. Now it’s time to analyze the results we’ve obtained and transcribe them into our assignment or work report. The ‘Results’ and ‘Share’ menus are for this purpose.
The menu ‘More options > Results > Summary’ displays information on all the thermodynamic elements we have calculated.
In this window, the first section displays the exercise settings, that is, the parameters used to calculate the thermodynamic properties. It is important to remember that different settings will yield different property values.
Next, the second and third sections display the properties of the thermodynamic states and processes, respectively. To avoid information overload, only the properties selected by the user in the ‘Show Properties’ window are displayed.
The final section displays the properties of the calculated cycles. A cycle can be closed, but it can also consist of only one or two processes, that is, an ‘open cycle’. In this way, the sums of the properties of adjacent processes are always shown. As in the previous sections, only the properties selected by the user in the ‘Show Properties’ window are displayed.
The menu ‘More options > Results > Calculations’ displays information about the equations and procedures used to calculate all the thermodynamic states and processes in the graph.
This window contains step-by-step explanations for calculating the properties of the states and processes. It is useful for checking the results when performing these same operations manually. Remember to be careful with the units, as the property values must be in the same units as the equations. Also, keep in mind that the exercise settings determine the equations used and, therefore, the results.
The first section shows how the states were calculated. The calculation procedure depends on the substance being worked with and the reference state defined for that substance, so this information is shown first. Each state is then defined by two properties, and from these two properties, the equations used to calculate the remaining properties are shown. In the case of a perfect gas, the equations are simple, and the calculations can be followed one by one. In the case of an ideal gas, the specific heat is calculated from a complex function of temperature, so these calculations will be indicated as cp = f(T). In the case of real substances, all the equations used are complex, so only the procedure is shown.
The second section shows the calculations that must be performed to determine the process properties. First, the control system is shown, since the equation used to calculate the work of the processes depends on it. For each process, the algorithm used to solve for its internal energy and enthalpy increments is shown, and how, based on these and depending on the type of process, the heat and work of that process can be calculated.
The menu ‘More options > Results > Balances’ displays the results of the mass, energy, and entropy balances, as well as the boundary work of the processes.
It is important to remember that the equations and values of the balances depend on the exercise configuration. Therefore, you must ensure the correct configuration before checking these values.
The first section displays the mass balance for each thermodynamic state, considering the mass of the processes entering and leaving the state. When calculating a control mass system, the balance verifies that the initial mass of the state equals its final mass. When calculating a control volume, the balance verifies that the mass entering the state equals its mass leaving it. There are special cases, such as the end states of an open cycle (the states where a cycle begins and ends), where the mass balance is not applicable.
The second section checks the energy balance according to the first law of thermodynamics for each process. The equation used in the energy balance depends on the exercise configuration, specifically the control system and the selected sign convention.
The third section displays the boundary work for each process. This check is useful when the process involves dissipative work and/or increases in its kinetic or potential energy, properties managed in the ‘Energy Balance’ window.
The final section is the entropy balance for each process. It’s important to remember that, to verify this balance, the temperature units used in the calculation must be absolute, i.e., Kelvin or Rankine.
The ‘More options > Share’ menu contains submenus for exporting your results to other applications.
Depending on the selected submenu, you will share either text or an image:
Summary: Text with the configuration and properties of the states, processes, and cycles.
Calculations: Text with the configuration and equations for calculating the states and processes.
Balances: Text with the mass, energy, and entropy balances, and boundary work.
Selection: Text with the states and processes selected on the main screen.
Graph: Image of the main graph and its scales.
Screen: Image of the main screen.
Thermonator: Text with the link to download Thermonator.
After selecting the text or image to share, a dialog box appears asking you to choose the application where you want to export this data. These applications are installed on your mobile phone, so they may vary from user to user: Mail, WhatsApp, Facebook, Instagram, X, TikTok, Reddit…
