Isothermal Expansion of Supersonic Flow

In summary, the conversation discusses the thermodynamics of a standard converging-diverging rocket nozzle and the relation it has with temperature. The relation assumes an adiabatic process, but the speaker is curious about the effects of holding the temperature constant. They mention the need for further research on the thermodynamics of jet engine combustion chambers and reheat systems to answer their question.
  • #1
Geometrian
3
0
Hi,

In a standard converging-diverging rocket nozzle, we have (ex.) the relation:[tex](1-M^2)\frac{dV}{V}=-\frac{dA}{A}[/tex]By substituting in definitions, we can obtain[tex]\left(1-\frac{V^2}{\gamma R T}\right)\frac{dV}{V} = -\frac{dA}{A}[/tex]This shows the dependence on temperature.

The relation assumes that the gas expands, accelerates, and cools in an adiabatic process. I would like to know what would happen if the temperature were instead held constant (i.e., by adding energy as the gas expands and accelerates)--but I have been utterly unable to find appropriate equations to replace the isentropic flow relations in the derivation.

What equations apply in this situation?

Ian
 
Science news on Phys.org
  • #2
Do some research on the thermodynamics of jet engine combustion chambers and reheat systems .
 
Last edited:

FAQ: Isothermal Expansion of Supersonic Flow

1. What is isothermal expansion of supersonic flow?

Isothermal expansion of supersonic flow refers to the process in which a gas or fluid expands at supersonic speeds while maintaining a constant temperature. This occurs when the gas is allowed to expand into a larger volume without any heat transfer or work done on the gas.

2. How does isothermal expansion of supersonic flow differ from adiabatic expansion?

In isothermal expansion, the temperature of the gas remains constant, whereas in adiabatic expansion, the temperature decreases as the gas expands. This is because in isothermal expansion, heat is transferred to the surroundings to maintain a constant temperature, while in adiabatic expansion, no heat is transferred.

3. What factors affect the isothermal expansion of supersonic flow?

The isothermal expansion of supersonic flow is affected by the initial temperature and pressure of the gas, the properties of the gas such as specific heat and molecular weight, and the expansion ratio, which is the ratio of the final volume to the initial volume.

4. What are the applications of isothermal expansion of supersonic flow?

Isothermal expansion of supersonic flow has various applications in engineering and science, including in the design of supersonic nozzles for rocket engines and in supersonic wind tunnels used for aerodynamic testing. It is also used in the expansion process of gases in refrigeration systems.

5. How is the isothermal expansion of supersonic flow calculated?

The isothermal expansion of supersonic flow can be calculated using the isentropic flow equations, which take into account the initial conditions of the gas and the expansion ratio. These equations can be solved using numerical methods or by using tables and charts for specific gases.

Back
Top