how does the air get compressed ? - (in a vehicle doing 30 - 180 mph)
What am I missing here?
His question about preparation of the oxidizer emboldened above. You need compression to raise the temp & density of the fuel-air mixture for proper combustion in a jet/ICE configuration. However you also said you want this thing to operate nearer to 1 bar (presumably on the infeed side) while producing supersonic combustion (detonation); otoh the known ways of doing that involve explosives. At which point we're getting into unconventional fuel sources in order to pull off this 1 bar feed-side fuel-oxidizer monopropellant solid state detonation gas generator.
how does the air get compressed ? - (in a vehicle doing 30 - 180 mph)
What am I missing here?
His question about preparation of the oxidizer emboldened above. You need compression to raise the temp & density of the fuel-air mixture for proper combustion in a jet/ICE configuration. However you also said you want this thing to operate nearer to 1 bar (presumably on the infeed side) while producing supersonic combustion (detonation); otoh the known ways of doing that involve explosives. At which point we're getting into unconventional fuel sources in order to pull off this 1 bar feed-side fuel-oxidizer monopropellant solid state detonation gas generator.
My research says the minimum viable pressure to drive the 3cm RDE would be 21lbs, or 1.5bar. This would be fed by the compressor wheel.
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 04 Apr 2023, 22:29
by vorticism
Is that the pressure of the fuel, the oxidizer? Air? What fuel is being specified for that arrangement?
Don't really want to drag this out further since we know what the 2025 power unit will be, but keep in mind that the RDE info out there you will find will probably be within the realm of rocketry, in which case, refer to all the points I made above.
Is that the pressure of the fuel, the oxidizer? Air? What fuel is being specified for that arrangement?
Don't really want to drag this out further since we know what the 2025 power unit will be, but keep in mind that the RDE info out there you will find will probably be within the realm of rocketry, in which case, refer to all the points I made above.
I understand. This was based upon the turbo outlet pumping into a second "scroll" and adding propane to the mixture in that chamber before the fuel/air is pushed into the RDE at 21psi.
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 04 Apr 2023, 23:10
by vorticism
Gotcha. Well it would be interesting to see more specifics. Do you have a link to the article? What was the application?
Gotcha. Well it would be interesting to see more specifics. Do you have a link to the article? What was the application?
It was a Twitter spaces chat..
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 29 Apr 2023, 02:44
by Holm86
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 29 Apr 2023, 14:06
by Tommy Cookers
majorly cutting the fuel energy has kept ....
the 'boost' low (avoiding the forecast need for 2-stage compressing etc)
major scope for super-high AFRs eg stratified charge (more heat dilution even less energy dumping to coolant & exhaust)
super-high AFRs will be supported by increase in fuel explosive range with its increased alcohol etc content
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 03 May 2023, 00:32
by gruntguru
According to the video, Lambda 2.8 is the limit under the new rules although I think the video assumes VE of 100+% and we know the current cars are less than 100% (due to Miller cycle operation).
Lambda 2.2 is frequently seen in TJI research papers. As Tommy says that could be increased with main-chamber stratification.
Gotcha. Well it would be interesting to see more specifics. Do you have a link to the article? What was the application?
It was a Twitter spaces chat..
so the RDE is powered by a turbo generator, which powers the turbochargers and the MGU-H??
No. Imagine a standard MGUH Turbo charger, with the RDE built into the center as a combustion chamber with no moving parts. So the impeller feeds the RDE, fuel injected into RDE, RDE exhaust feeds the exducer, exducer spins impeller and MGUH.
Re: 2025/2026 Hybrid Powerunit speculation
Posted: 09 May 2023, 17:26
by DenBommer
Ok, so there's no turbo generator involved at all?
I saw in one of your previous post your idea (dream) for the PU of 2030, I hope they really do this
Maybe a stupid question, but if I'm correct is the RDE+turbo+MGUK a turbo generators on itself?
My idea was to put the rde between the impeller shell and the exducer shell (where the current turbo designs use a cartridge bearing), with the MGUH connected to the shaft on the impeller end. Something like 600V/300A because of high RPM that would drive electric motors front and rear. In this setup, there would be no battery (maybe small ultracap array for electric hysteresis). As driver demands torque, RPM of the gas generator changes to deliver more amperage. Pretty simple imho.
