How to create a tcmap in ricardo from a 2-d plot of pressure vs mass flow [Archive]

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Seeger

10-19-2009, 08:31 AM

I was interested in modeling the garret 1241 turbo in Ricardo and i was able to map the compressor form the pdf i found garret 1241 (http://www.turbobygarrett.com/turbobygarrett/images/catalog/Turbochargers/gt12_images/GT1241-756068_1.pdf).
I am confused as to how to get 4-d data form a 2-d plot and a maximum efficiency.

Seeger

10-19-2009, 08:31 AM

Professor Gas Can

10-19-2009, 10:11 AM

Not sure how Ricardo is setup (sorry, use GT-Power), but there should be a compressor map template you can make with the 4 inputs (Turbo Speed, mass flow rate, pressure ratio, efficiency). Then you basically start with constant turbo speed and reference the appropriate MFR, PR and Eff...then move to the next constant turbo speed. Or you can just ask Garrett for the compressor map in tabular form...or ask Ricardo how to input a compressor map.

PBnG

10-19-2009, 01:06 PM

The compressor map is 4D. http://fsae.com/groupee_common/emoticons/icon_smile.gif The two axis are mass flow and pressure ratio. The relief (oddly shaped circles) defines efficiencies (much like altitude on a relief map.) The bold curves define a set turbine RPM. Make sure to choose at least 4 points per RPM curve and at least 5 RPM curves for WAVE to interpolate. It's best if you let WAVE find the max efficiency point.

The exhaust turbine map is only two dimensional. *Warning: large assumption to follow!!!* It is fairly safe to assume constant efficiency and that the curve is roughly the same for every RPM in the low operating range. This is a big assumption but should get your model working promptly. However, the 4D information for the exhaust turbine should be easily available from Garret. I would just send them an email.

Cheers,