CFD Thermodynamics flow in Angular momentum system

In summary: So, without any outside influence, the container will eventually settle into a state where the energy flow rates are the same. In summary, angular momentum is conserved in a closed system.
  • #1
Leef
12
1
Angular momentum is conserved in a closed system. Is thermal isolation required too?

An example special case in mind is a closed cavity high speed rotation.

It contains high pressure gas and the thermal flow is driving convection currents creating turbulence and or a heat pumping loop. Energy in must = Energy out so even in extreme cases with high thermal flows does Angular momentum Energy become a factor?
 
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  • #2
Not sure what you mean by "angular momentum energy". Do you mean rotational energy?
 
  • #3
Chandra Prayaga said:
Not sure what you mean by "angular momentum energy". Do you mean rotational energy?

I have 2 main energy flow paths.
A. Strictly a thermal temperature differences to and from container.
B. Energy to maintain a rotation rate of container.

If Angular momentum is conserved in a closed system / the closed container B will always over time settle out and remain 0.

From that then A should settle out to a fixed energy flow rate.

Well I am almost a closed system on the rotation part other than pure Thermal Energy

I think I am ok long as there is no mass exchange in or out of the container Angular momentum will be conserved. So I am looking for a more complete definition or explanation from the thermodynamics and CFD side.

If you start looking at the rotational kintic energy (RKE) it gets complicated fast. Hot gas far out from center in the container will flow inward thus gain RKE, cool gas will flow from center out losing RKE. Then add in the ideal gas pressure / tempura changes it gets very thermodynamics involved. Also there will be turbulence / wall drag on inside wall of container.

It should act like a heat pump and energy is not free so there should be rotational energy input or total thermal flow should be more in than out to support the internal turbulence flow.
 
  • #4
I don't mean to sound rude here, but you've mixed together about a dozen different terms, and only about half appear meaningful in the context you used them (for example, CFD in the title). That's making it hard to understand what you are asking. However:

We can say that in a closed container, energy in and energy out (mechanical or thermal) must be equal when the system is in a steady state (not changing). If there is something rotating inside and the energy flow rates are constant, that means it must rotate at a constant rate.
 

FAQ: CFD Thermodynamics flow in Angular momentum system

What is CFD?

CFD stands for Computational Fluid Dynamics. It is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems related to fluid flow and heat transfer. CFD is commonly used in engineering and scientific research to study and optimize the behavior of fluids in various systems.

How does CFD relate to thermodynamics?

Thermodynamics is the study of energy and its transformation in systems. CFD is often used in conjunction with thermodynamics to analyze and model the behavior of fluids in thermodynamic systems. CFD can provide detailed information on the flow patterns, temperature distribution, and other thermodynamic properties of a fluid within a system.

What is the significance of angular momentum in CFD?

Angular momentum is a fundamental concept in fluid mechanics and plays a crucial role in CFD simulations. In a thermodynamic system, angular momentum is conserved, meaning that the total angular momentum of the system remains constant. CFD uses the conservation of angular momentum to accurately model the flow of fluids in systems with rotating components such as turbines and pumps.

How does CFD use numerical methods to solve thermodynamic problems?

CFD uses numerical methods such as finite difference, finite volume, and finite element methods to discretize the governing equations of fluid flow and thermodynamics. These methods break down the continuous equations into a discrete form that can be solved using computers. CFD also uses algorithms to solve these equations iteratively, providing accurate and efficient solutions to complex thermodynamic problems.

What are some applications of CFD in thermodynamics?

CFD has many applications in thermodynamics, including analyzing heat transfer in engines, optimizing the performance of heat exchangers, and designing efficient cooling systems. It is also used in the design and optimization of aircraft and automobiles to improve aerodynamics and reduce fuel consumption. CFD is also commonly used in the design of power plants, chemical reactors, and other industrial processes to improve efficiency and reduce costs.

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