saviour stivala wrote: ↑03 Mar 2022, 22:33
. . . And with waste-gate closed and turbine being powered by exhaust gas pressure. I doubt how much use it can make of blowdown pulse
.
energy. This because as far as I know all four PU’S on the grid uses an exhaust pressure collector for a path for exhaust gases to turbine and not the proper exhaust piping conductive to make best use of blowdown pulse energy.
There are many images showing Formula 1 turbine housings with 2 inlets and only 3 cylinders connected to each inlet. The
only reason for this is to harvest blowdown energy.
.
( 07 oct 2014 ‘’blowdown energy is free’’ by GR – To harness this energy the pressure pulse must be piped to the turbo without adding pressure to the exhaust of any cylinder)
. . . to accomplish this, each nozzle or volute of the turbine must be connected to no more than one exhausting cylinder at any time. On four stroke engines this means that no more than 3 evenly spaced cylinders can be connected to each nozzle. Connecting more than 3 cylinders to a nozzle would mean that at some time during its exhaust stroke, each cylinder will be sharing the nozzle with a high pressure blowdown pulse from another cylinder - greatly increasing the backpressure on the cylinder on exhaust stroke to the detriment of pumping work and exhaust gas removal for that cylinder.