those hundreds of millions of turbocharged road vehicles that have been built ......saviour stivala wrote: ↑23 Feb 2022, 10:08The wright turbo compounding used a ‘blow-down’ turbine and not a ‘pressure turbine’.
The formula 1 turbo uses a pressure turbine .....
Correct. The whole point of divided turbine housings is to provide separate nozzles so that no more than 3 even-firing cylinders are connected to each nozzle. (The Wright Turbo Compound had two cylinders connected to each nozzle and three nozzles per turbine.) This allows the turbine to harness the energy contained in blowdown pressure pulses which are higher than the average exhaust pressure.godlameroso wrote: ↑23 Feb 2022, 20:12Aren't they all mixed flow turbines? They work with both pressure and kinetic impulse. The casing jets/nozzles air into the turbine wheel, exchanging pressure energy for kinetic energy, the wheel once again jets/nozzles air into the exhaust. Once again trading pressure energy for kinetic energy.
https://www.energy.gov/sites/default/fi ... k=Wcwy8dAU
I find the relationship between all those variables fascinating. Once you understand the relationship everything becomes damn near intuitive.gruntguru wrote: ↑25 Feb 2022, 01:49Correct. The whole point of divided turbine housings is to provide separate nozzles so that no more than 3 even-firing cylinders are connected to each nozzle. (The Wright Turbo Compound had two cylinders connected to each nozzle and three nozzles per turbine.) This allows the turbine to harness the energy contained in blowdown pressure pulses which are higher than the average exhaust pressure.godlameroso wrote: ↑23 Feb 2022, 20:12Aren't they all mixed flow turbines? They work with both pressure and kinetic impulse. The casing jets/nozzles air into the turbine wheel, exchanging pressure energy for kinetic energy, the wheel once again jets/nozzles air into the exhaust. Once again trading pressure energy for kinetic energy.
https://www.energy.gov/sites/default/fi ... k=Wcwy8dAU
This means that any turbocharger can be operated as either a pressure turbine, a blowdown turbine or a mix. Even the Wright TC could have been operated as a mixed turbine by simply reducing the nozzle size to the point where average exhaust pressure is above atmospheric. This would have increased the turbine power but at a cost to crankshaft power due to increased exhaust stroke pumping energy.
From: https://x-engineer.org/twin-scroll-turbo/Twin-scroll turbochargers are using both thermal and pulse (pressure wave) energy of the exhaust gas in order to obtain mechanical work to drive the intake air compressor.
isn't that second sentence just .... wrong ?saviour stivala wrote: ↑23 Feb 2022, 20:50The blowdown turbine is an ‘impulse turbine, were the gases are conveyed to the turbine wheel through separate Siamese pipes.
A pressure turbine as used by the F1 turbo, the gases of all cylinders are conveyed to the turbine wheel through a collector pipe, with two possible paths. ether through a waste-gate or through the turbine wheel.