Disclaimer: this thread is NOT about electric superchargers.

I was reading This Thread about "electric superchargers". Read on.

I got a little inspired and decided to do some modeling on HYSYS, a program made for plant design such as chemical plants, distillation, etc. There is also a simple compressor model, so I decided to do some simulations.

The basic model should be valid for turbo, SC, whatever.

Just as a couple of examples, I tried modeling a 9psi compressor and a 3psi compressor. Check out the data:

at 80% adiabatic efficiency, 9psi of compression, and intake temperature of 25 degrees C, 32 lb/minute of air:

The energy required to compress this is about 13 kW, which is equivalent to about 17.6 horsepower. This kind of calculation can let you know about how much HP your S/C is leeching... I'm still not sure what I can do with data about turbo's however. All I know is energy is energy... so SOMEHOW the blower needs to get that 13kW to do the compression. In an S/C you will derive the power from your pulley, in a turbo you will sap this energy from exhaust gases obviously.

The outlet temperature will jump to 80 degrees C.

For the 3 psi compressor...
45 degrees C outlet
6.5 horsepower
4.9 kW


If this is interesting to any of you F/I guys, give me the following parameters and I can run a simulation for you.

-Inlet air temperature
-Inlet pressure (gauge pressure, usually this will be about 0psi)
-Outlet pressure (how much are you boosting)
-Flow rate of air in whatever units you want, I can convert it
-Adiabatic efficiency of your blower, if you know it.

The better and more realistic the parameters, the better and more interesting the data will be.

Hope this is of some interest...

-Mike

 

You're too smart for your own good. That's pretty cool though

 

ok so for us SC guys running 9psi, the parasitic losses are 17.6hp according to your data - that's crank hp I'm assuming?

this is for centrifugal/turbo designs and not roots/twinscrew style compressors right?

I'm coming to the conclusion that centrifugal sc's are more effiecient at higher boost than lower boost

 

It is a fairly simple calculation, I didn't specify what kind of turbine it uses.

17.6hp is just a power measurement, that is why it can be converted to kW.

All this calculation tells you is: at a certain inlet temperature and pressure, to get to X outlet pressure takes Y power.

So, anyone have some data-logged parameters they want me to run through the program? Most of this stuff you can get with cipher I think. A big parameter is how much mass flow of air there is. I think the value I used is for 7krpm at WOT, something like that... then again it's an approximation.

 

off topic, but what is it with all the blue faces in the avatars?

 

The premier members have started a war against noobs, with a braveheart theme.