Turbo charger with a flywheel

[Scuderia Nuvolari]

Would a simple small flywheel help the compressor stay spooled up when it gets up too
125000 rpm.
Would it help keep the strain off of the mguh?
Would it help keep the electrical power demand down?
Would a small flywheel help keep the compressor at 125000 rpm at all engine rpms?

[flynfrog]

it would stay spooled longer it would also take longer to spool probably a net loss.

[riff_raff]

A flywheel would be a poor way to transfer energy thru a turbocharger. If the flywheel were large enough to have sufficient inertia to contribute reasonable amounts of energy to a turbo-compressor, it would also produce sufficient lag in the turbocharger spool to kill throttle response.

[Greg Locock]

At least on diesel engines of a certain vintage, the inertia of the turbo is tuned to maximise the enegry derived from each pressure pulse in the exhaust. As such a flywheel would be a disadvantage. Unfortunately I haven't got plot showing this but it is the fundamental reason why the exhaust silencing system on a turbo car can be relatively straightforward, the annoying low frequency contribution has already been eliminated.

[Tommy Cookers]

here we have a turbine sized to draw about 4 times the power needed for turbocharging
an electrical machine of at least 90 kW
and a 'turbo' impeller
all joined together and rotating at 125000 rpm

how much energy is stored in that lot already ?

c'mon you number-crunchers, you know you want to !!

[riff_raff]

Well designed turbochargers do not store much energy. Instead they transfer energy from the exhaust gas to the intake gas as efficiently as possible. This requires the turbine and compressor performance characteristics to be closely matched over the operating range of the engine. And so there is a balance between the work of the compressor and turbine.

In a conventional turbocharger, the only potential for storing energy is by increasing the rotational speed of the spool. But due to the low polar inertia of the spool, the total amount of energy it can absorb or return to the engine airflow is limited. However, due to the very high rotational speed of the spool, the amount of energy that it can transfer from the exhaust gas to the intake gas is quite substantial.

[langwadt]

here we have a turbine sized to draw about 4 times the power needed for turbocharging
an electrical machine of at least 90 kW
and a 'turbo' impeller
all joined together and rotating at 125000 rpm

how much energy is stored in that lot already ?

c'mon you number-crunchers, you know you want to !!

1/2*I*W^2 so at 125000rpm probably quite alot. the rules allow the mgu-h to be cluched, I wonder if that could used to make
something similar to the Williams fly wheel KERS? disengage MGU while braking storing the energy in the rotor, reengage
to spin up turbine when going back on trottle

[Scuderia Nuvolari]

Can you use this type of system to keep the turbine spooled up? I believe that the williams system is in a partial vacuum, which adds more weight. Would a simple flywheel coupled with the mgu be able to keep the compression at maximum without adding a lot of weight or using too much electrical power. If something like this could work then you would have excellent power at any rpm and the compressor would stay at critical rpm.

[langwadt]

Can you use this type of system to keep the turbine spooled up? I believe that the williams system is in a partial vacuum, which adds more weight. Would a simple flywheel coupled with the mgu be able to keep the compression at maximum without adding a lot of weight or using too much electrical power. If something like this could work then you would have excellent power at any rpm and the compressor would stay at critical rpm.

the partial system is there to reduce the loss from drag. The reason to use some form or flywheel effect would only to skip the conversion to electricity and back via the batteries and instead store the energy in the rotor inertia

though I have no idea of the numbers add up

[riff_raff]

Can you use this type of system to keep the turbine spooled up? I believe that the williams system is in a partial vacuum, which adds more weight. Would a simple flywheel coupled with the mgu be able to keep the compression at maximum without adding a lot of weight or using too much electrical power. If something like this could work then you would have excellent power at any rpm and the compressor would stay at critical rpm.

With conventional turbochargers the compressor and turbine are coupled and spin at the same rpm. The compressor and turbine are designed to work in equilibrium and provide the best compromise of flexibility and efficiency. If the turbine is spooled up, that means the compressor is also spooled up. If the turbine is spooled up without any significant exhaust gas flow, that would mean the engine is operating without any load, and thus there is no airflow demand from the compressor. With no airflow demand from the compressor, unless the compressor intake was throttled, the work done by the compressor would simply result in wasted heat energy in the intake airflow.

[Scuderia Nuvolari]

So that seems too mean that a supercharger is just a waste of energy in the intake manifold at low rpm.