New answers tagged thermodynamics
0
votes
Would this work as a solid fuel heat engine that didn't need to boil water?
Your design can be approximated using the Brayton cycle with recuperation. Search on that for the details.
- 14.3k
0
votes
Would this work as a solid fuel heat engine that didn't need to boil water?
The problem I can see is that there's no valve system to ensure that exhaust gases are directed to the decompressor. The entire interior of the engine will be at more or less the same pressure.
The ...
- 224
0
votes
Would this work as a solid fuel heat engine that didn't need to boil water?
Every Jet-Engine works like that. They only miss the heat-exchanger.
- 1
0
votes
How to Link between Stoichiometry, Energy Content of a Fuel, Combustion in a Cylinder-Piston, and Otto-Cycle, Compression Ratio, & Thermal Efficiency?
Where is the combustion occurs in the Otto P-V diagram? At point 2?
Yes
Is that calculations from step 1 to step 10 correct?
Maybe, but what are you trying to accomplish? It looks fine on the ...
- 6,534
0
votes
How to calculate the required power to pump out (to vacuum) a container?
Following on from @kamran's answer and ignoring the slight change in pressure as the 1 L piston moves, you can calculate the force required at each step as $ F = \Delta P \times A $ (pressure ...
- 10.3k
1
vote
Accepted
What is the correct way to calculate the efficiency of a heat exchanger?
Effectiveness using $\epsilon = \frac{q_{act}}{q_{max}}$ seems to be most general. It assumes comparing 2 cases and I would choose comparing cases where inlet temperatures and flowrates are fixed for ...
- 1,077
0
votes
Accepted
Electricity generation from sand particles in airstream hitting surface
This seems to be your question:
What if we use concentrated sunlight to heat air (e.g. to 300° C) and blow that air at high speeds to fire fine sand on some surface and continuously do so to generate ...
- 6,534
0
votes
What is the correct way to calculate the efficiency of a heat exchanger?
A good measure I think for what you need is Tout_Coldside/Tin_Hotside if you are trying to heat a cold fluid. Where if the Tout were equal to Tin_hotside then you would have a "100%" ...
- 326
2
votes
Electricity generation from sand particles in airstream hitting surface
The energy required to pick up and blow the filings at the surface will exceed the truly tiny amount of charge separation that this device will generate, so it is a net losing proposition.
This is not ...
- 14.3k
0
votes
Volume of air going through a hole with a temperature difference, and kWh of energy
One starting approximation can be using The air density difference as the driving force and equating the potential hydrostatic energy to the kinetic energy of the flow.
Assuming h and P are equal on ...
- 22.1k
0
votes
Stirling Engine Cooled Engine
Hypothetically yes. However the existing engine must run at a peak torque/rpm to run the engine to act as a heat pump.
Much like turbochargers, some companies are installing a small battery to run the ...
- 544
0
votes
What is the theoretical explanation of flow work/energy?
In theory of this example, there would be no flow work done. If we add friction then the friction gets transfered to heat and would subsequently increase the pressure. Even at a steady state, there ...
- 27
0
votes
How to interpret the Otto Cycle PV diagram?
Nothing in your logic is wrong, in my understanding, but I'm not sure what your question or issue is.
PV diagrams assume constant particle number
Yes, there is an unchanging fluid mass during stages ...
- 111
Top 50 recent answers are included