Foo - A Question to Excel Users

My ultimate aim is to create a line graph showing the relationship between the aerodynamic drag force and velocity of a bike as it moves through the air.

I am using a simple, straightforward multiplication formula with five parts. Four of these five parts remain constant. The part that varies is the part representing velocity.

I want to measure drag force all the way from zero meters per second right up to forty five meters per second, with as much resolution in between these two figures as possible.

Please help me by telling me what to type into Excel and exactly where to type it?

Nevermind. I seem to have the problem solved. But if anyone knows of a better math’s/graph plotter program than Excel, please let me know.

Maybe even a program that can plot graphs from data imported from Excel?

There are better chart programs out there, like Minitab, Statgraphics and JMP. However, for the one or two charts you are doing, I'd just stick with Excel. Statistica also makes a very powerful data analysis and graph generator. You can google any of these names for websites and information. These are just a few, I like Minitab and have used it the most.

Access Database is also nice, but in one respect, cumbersome. If you screw up, you start over, there is no undo/redo!http://img52.exs.cx/img52/4566/i7pfrusty.gif

Thanks for the recommendations. I will take a look at them.

gnuplot!
A couple of hours of learning curve, but definitely nifty.

Added to the list. Thanks.

Are you just talking about the bike itself? I mean, bikes don't move through the air all by themselves and the different shapes and sizes of riders are going to affect that equation dramatically.

Are you just talking about the bike itself? I mean, bikes don't move through the air all by themselves and the different shapes and sizes of riders are going to affect that equation dramatically.

I am including the bike with rider in my calculations. To account for both I have estimated the total frontal area and I am using a drag coefficient of 0.9, that I got from a table of coefficients for different types of bikes and other vehicles.

Minitab!

I'm confused about exactly what you're doing though. Are you actually taking measurements in a wind tunnel or through other experimental means, then plotting the points of data you've gathered?

Or, did you come up with a formula, which you're going to solve for several values, then plot those values?

If the latter, just get software that will plot the forumula itself, rather than solving for and plotting values.

Minitab!

Thanks. On my list!


Or, did you come up with a formula, which you're going to solve for several values, then plot those values?

Yep, I am just using a formula. I am trying to estimate, and then plot my findings on a graph, the drag force the bike I am designing will meet at various speeds.


If the latter, just get software that will plot the forumula itself, rather than solving for and plotting values.

Will Minitab do this? If not, could you recommend a program that will, please?

gnuplot!
A couple of hours of learning curve, but definitely nifty.


Couple of hours! More like a couple of years learning computer programming skills. Even downloading the thing was a stressful ordeal. I do not even know if what I did DL was even the right file! Thanks anyway.

Minitab will likely handle anything you can dream up.

Can you show us the formula(s) you're trying to work with?

F = ½PV²Cdf

Where:

F = force (N)
P = air density (1.225 Kg/m³ (standard))
V = velocity (m/s)
Cd = coefficient of drag
f = frontal area (of vehicle) (m²)
M = mass (Kg)


Excel is really pi$$ing me off now. Using increments of 1 meter for speed was fine when it came to creating a line graph. Excel simply put 1 through to 45 in the x axis. But when I tried using increments of 0.1 meters, and then increments of 0.5 meters, Excel, for some unknown reason, put 1 through to several hundred on the x axis. So anyone looking up the air drag for 98 m/s, for example, would in fact see the force of a much slower velocity!

The graphs it is generating are false.

Here are a couple other data and charting programs, http://www.systat.com/products/SigmaPlot/ Sigma Plot has been around forever and produces beautiful charts.

And xcelsius takes your Excel data and produces very nice charts http://www.xcelsius.com/Land/g_charts.html?extcmp=xcel_google_charts_chart%20software

A million years ago I used mathCAD. I guess it's not around anymore. Anyways, once you figure it out, I'd like to see a graph of the results.