Quote:
Originally Posted by thorpie
The y values for each contour are separate columns. The curve # values separates them into columns.
The consumption lines in the second chart are actually contours, they just end up squashed flat.
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Thanks! This is a good plotting technique but my BSFC numbers are part of a scatter plot.
Quote:
Originally Posted by thorpie
. . .
These values are calculated as KwGross/SpeedKmh*BSFCinGrams/1000*0.74*100).
As in 1 hour @ 100 km/hr @ 50 kw gross = usage of 50kwh/100 km and 1 kwh = BSFCinKg/0.74 kg/litre fuel weight.
The theoretic minimum fuel consumption would be a curve joining the end points of the lines.
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I thought that was one of the clever parts of the spreadsheet. I'm not ready to go there until I'm happier with my BSFC data from the field.
Quote:
Originally Posted by thorpie
. . .The code that calculates speed from power input is in the macro module. Please feel free to use that elsewhere. It needs to solve a quartic (power 4) equation and is a pain to have to recreate.
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Interesting. I recently came across the EPA drag formula from SAE 2009-01-1322:
A*(v**2) + B*(v) + C
A - coefficient proportional to aerodynamic drag
B - coefficient proportional to a linear drag function
C - fixed, typically rolling drag
v - velocity
I briefly saw a table of these values used by the EPA to calculate some the EPA mileage numbers.
Thanks, excellent work.
Bob Wilson