# Homework Help: Physics of Turbochargers

1. May 6, 2004

### Darken

For my physics class, I need to do a project on something that has physics involved in its operation. I chose a turbo charger in a car, but the only physics I can actually say is being demonstrated, is momentum. Is there other physics princibles that are involved.

(A turbo charger works by using the exhaust to spin a turbine, which increases the air pressure that is being inserted into the cylinder. Hence, more air = more fuel = more power.)

Last edited: May 6, 2004
2. May 6, 2004

### NateTG

Well, let's start with the natural gas law - this affects how much increase in air you get for a particular pressure.

There are a whole slew of thermodynamics things you can look at like how much energy is normally thrown away by car exhaust (temperature and pressure), how using a turbocharger affects the energy density and efficiency of the engine. More thermo - you could discuss why hooking an exhaust fan directly in to power the wheels is counter-productive, and what the difference between superchargers and turbochargers is. You can discuss the natural gas law, and how the increased air pressure affects the ideal mix, and the flash point of the engine.

You should also be able to discuss the difference between gasoline and diesel engines (diesel ignition) and why turbocharging is much more interesting in diesels.

You can also compare a turbo-charged engine to a turbine engine (which consist of a compressor, turbine, and burning chamber -- sound familiar?).

You can look into exhaust tuning (compare to pulse jet engine), and how exhaust turning and turbochargers interact. Discuss that explosion fronts typically travel at the speed of sound.

3. May 6, 2004

### Darken

Thanks

Thanks Nate.

I also thought that I could possibly tie into the conservation of angular momentum as well, but that's still a mystery to me.

4. May 6, 2004

### NateTG

Not really. You could do some stuff with torque if you wanted to analyse the speed of the turbine, but there isn't a whole lot of angular momentum stuff in a turbochargers.