# How could I integrate the changing location of the midpoint of a streamlined body into either the drag or reynolds number?

Because the volume and surface area is constant I am not sure how to represent the change in flow dynamics - laminar to turbulent.

(sorry if this is a stupid question, I am a biologist and I can't seem to find any material that tackles this problem)

If I could calculate the Cd it would help, but I am not sure that I can.

I do have some data which represents the 'stability' of each shape during testing.

• You might not be able to get an answer here, but your chances would be a lot better if you would give more information on the shapes & flow speeds. Are the cross sections all the same? Are they round? Are the lengths the same? What are they? Is the flow parallel to the long axis, or some angle? What is the flow speed? And so on... – D. Halsey Aug 28 '18 at 0:17
• Also, something about what the situation may be. Are these objects falling through some fluid under their own weight, etc? – D. Halsey Aug 28 '18 at 0:25
• This sounds to me like a situation where you need to sit down with an expert in this field. I'd be surprised if this site would be able to give you a useful result. Even the best electrician needs to call a plumber sometimes. :-) – StephenG Aug 28 '18 at 0:27
• same size, length, volume and cross-section. Held in water with a constant flow parallel to the long axis. Flow speed is 2000L/s or 0.0005555556 m^3/s. The only change is the location of that mid-point (distance from the front) - eg 0.1, 0.2, 0.3, 0.4 (proportion from front). – Ingrid Aug 28 '18 at 0:33
• Thanks for the comments guys. I am probably reaching a bit with this particular problem. – Ingrid Aug 28 '18 at 0:38