Generating BSFC Maps

[joemac42]

I am looking for software recommendations for fitting engine dynamometer fuel consumption data into iso-BSFC-line contour plots (e.g., BMEP vs RPM with lines of constant BSFC). What have you used in the past? What would you recommend? I have used SigmaPlot previously to do this but I have found it difficult to use. It requires the data to pass through a 3D smoothing sub-routine and the sub-routine fails on more than half of the data sets that I have put through it.

-Joe

 

[GregLocock]

Wow, that must be some crummy software.

If you want to roll your own it depends how much you want to spend, and how much you want to learn programming wise. Excel,

http://www.xlxtrfun.com/XlXtrFun/XlXtrFun.htm,

matlab, octave, python and R all offer some form of 3d plots, but the real question is how do you fit the surface to the random scattering of rpm vs bmep vs sfc triads. This requires decisions to be made - for instance you probably won't have good coverage in some parts of the bbmep/rpm axes, and you won't have even coverage in general, and how much smoothing do you want to apply?





Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[Lou Scannon]

Matlab has a good tesselation routine for plotting 3D data. As Greg says, be wary of zones where the data are limited or scattered.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[Panther140]

Labview and a fuel turbine meter might do the trick

"Formal education is a weapon, whose effect depends on who holds it in his hands and at whom it is aimed." ~ Joseph Stalin

 

[joemac42]

Panther - Data Acquisition hasn't been an issue for me. This is more about what to do with the data after it's generated to visualize areas of operation. That is often done with 2D iso-BSFC contour plots but even with 50-100 speed-load points, Iso-BSFC lines still end up requiring a fit of relatively sparse, randomly scattered data. There are always holes in the data and some sort of data smoothing is required over some areas of the map.

 

[Panther140]

joemac42 - Oh I see. I am pretty sure good ol fashioned microsoft excel has some isometric plots that you could look into using with your own macro to tailor it to the data you are using. Ill ask some guys in the lab at work what they might use for that

"Formal education is a weapon, whose effect depends on who holds it in his hands and at whom it is aimed." ~ Joseph Stalin