Talk:Heinkel HeS 40

Need a tag for cleanup by expert
I don't know how to add a tag to an article, never could figure it out. But there are a lot of problems. I started with fixing the place where the writer called the expansion ratio of hot gasses the "compression ratio". That is wrong. The compression ratio is how much the initial atmospheric air is compressed BEFORE burning fuel into it, also called "pressure ratio" on a jet compressor, I believe. The writer calls the process "similar to a six-cylinder piston engine" which will just confuse readers, since it is only similar in terms of the therodynamic process that occurs. The writer seems to be under the impression that on a car the "turbocharger" compresses the air, which is then combusted and expanded (calling this the "compression ratio"). On a piston engine the turbo only serves to PRE compress the air. The actual compression is done by the piston compression stroke, and phrasing it like that will just confuse readers. The six "cylinders" in this case ONLY serve as combustion chambers; ALL of the compression is done by the compressor, at a much higher ratio than most turbochargers use. Then the writer says "the power is extracted by the turbine, instead of the pistons". No, on a jet the power output is all in THRUST. The turbine only serves to draw off a little power to turn the compressor to continue the cycle. It's like talking about a turbocharged engine and saying "the turbine wheel takes the place of the pistons in extracting the power". The turbine wheel only serves to take off a little of the excess heat energy that the pistons DIDN'T utilize (although in a jet engine the turbine draws the power off before the main event, not after). If it was a turboprop or turboshaft the analogy might be more correct. There is really not much similarity between this and a "six cylinder engine" other than that both feature poppet valves to close off the compressed air while it's being heated. In the piston engine the valves close off the air BEFORE compression. In this jet they close off AFTER compression. In the piston engine, the same chamber serves for compression, combustion AND expansion, while in the this jet the chamber ONLY serves for combustion, the compression happening in the compressor and the expansion happening in the turbine and jetpipe. I tried to fix it a little, but it'd be better done by someone more practiced at wikepedia editing. 64.223.104.59 (talk) 05:59, 21 July 2020 (UTC)