A question about turbocharger

[ZHangYang]

Im doing a research recently, need to get the turbine spinning speed at different working conditions. Yet, lacking of equipments, does anybody know how to get the spinning speed by Mathematics method?
Thanks a lot!

[bobc455]

Originally Posted by ZHangYang

Im doing a research recently, need to get the turbine spinning speed at different working conditions. Yet, lacking of equipments, does anybody know how to get the spinning speed by Mathematics method?
Thanks a lot!

For a free-flowing application you would do a volumetric calculation based on the volume of the exhaust turbine and the volume of exhaust gas (combined with a few other factors like pressure drop). For a real-world application, you would then have to subtract the resistance from the compressor and friction...

-BC

[ZHangYang]

Originally Posted by bobc455

For a free-flowing application you would do a volumetric calculation based on the volume of the exhaust turbine and the volume of exhaust gas (combined with a few other factors like pressure drop). For a real-world application, you would then have to subtract the resistance from the compressor and friction...

-BC

if i get the pressure and the temperature of the exhaust gas, and the parameter after it passing through the turbine, is it enough? Is there any formulas I can use?

[GasSavers_RoadWarrior]

For a lot of data and calculations as it applies to vehicle turbochargers, look on a torrent search engine for "Maximum Boost" by Corky Bell.

[ZHangYang]

It seems a complicated question. I decide to check the information in the labrary first. Thank you for your help.

[bobc455]

Definitely not a simple calculation, and I'm not sure you'll find a simple formula. You definitely need a lot more information than just temperature and pressure, you have to know the geometry of the vanes and have a complete 3D model of the entire turbine system (as well as some information about the exhaust system to which it is attached).

Why are you looking to determine turbine speeds? Maybe there is another way to skin the cat...

-Bob C.

[kamesama980]

ask the manufacturer. They usually have volumes of info they can look up.

[GasSavers_bobski]

You should be able to find flow maps for most turbochargers online.
Here's an example:

[ZHangYang]

Now I realize that it is not a simple question. Maybe I should deal with it based on a computer software. But the direct way to solve the problem is to measure the turbocharger rotational speed by equipment, right?

[bobc455]

Again, not so easy - since many turbos spin at 30,000 to 60,000 RPM (and I've heard of some at 100k+ RPM), attaching equipment will most likely create additional drag (affecting your reading), and/or create a balance issue with the spinning turbine (which would cause it to self-destruct in short order). Besides, a tach to read 60,000 RPM is pretty highly specialized.

Are you trying to design a turbocharger?

-BC