Methodology for solving thermodynamics problems:
1. Known: State briefly in your own words for what is known.
2. Find: State concisely in your own words what is to be determined.
3. Schematic and Given Data: Draw a sketch of the system to be considered. Decide whether a closed system or control volume is appropriate for the analysis and then carefully identify the boundary. Label the diagram with relevant information from the problem statement.
Record all property values you are given or anticipate may be required for subsequent calculations. Sketch appropriate property diagrams, locating key state points and indicating, if possible, the processes executed by the system.
4. Engineering Model: To form a record of how you model the problem, list all simplifying assumptions and idealization made to reduce it to one that is manageable.
5. Analysis: Using your assumptions and idealizations, reduce the appropriate governing equations and relationships to forms that will produce the desired results.
It is advisable to work with equations as long as possible before substituting numerical data. When the equations are reduced to final forms, consider them to determine what additional data may be required. Identify the tables, charts or property equations that provide the required values. Additional property diagram sketch may be helpful at this point to clarify states and processes.
When all equations and data are in hand, substitute numerical values into the equations. Carefully check that a consistent and appropriate set of units is being employed. Then perform the needed calculations.
Finally, consider whether the magnitude of the numerical values are reasonable and the algebraic signs associated with the numerical values are correct.
1. Known: State briefly in your own words for what is known.
2. Find: State concisely in your own words what is to be determined.
3. Schematic and Given Data: Draw a sketch of the system to be considered. Decide whether a closed system or control volume is appropriate for the analysis and then carefully identify the boundary. Label the diagram with relevant information from the problem statement.
Record all property values you are given or anticipate may be required for subsequent calculations. Sketch appropriate property diagrams, locating key state points and indicating, if possible, the processes executed by the system.
4. Engineering Model: To form a record of how you model the problem, list all simplifying assumptions and idealization made to reduce it to one that is manageable.
5. Analysis: Using your assumptions and idealizations, reduce the appropriate governing equations and relationships to forms that will produce the desired results.
It is advisable to work with equations as long as possible before substituting numerical data. When the equations are reduced to final forms, consider them to determine what additional data may be required. Identify the tables, charts or property equations that provide the required values. Additional property diagram sketch may be helpful at this point to clarify states and processes.
When all equations and data are in hand, substitute numerical values into the equations. Carefully check that a consistent and appropriate set of units is being employed. Then perform the needed calculations.
Finally, consider whether the magnitude of the numerical values are reasonable and the algebraic signs associated with the numerical values are correct.