- #1
spearo
- 8
- 0
Hi,
I am having trouble calculating the reynolds number for 2 spear shafts underwater. The two shafts vary in diameter and velocity. The tips are identical, stream lined to a fine point so the flow should be laminar. Both spears are 1.9304 m long. The diameters are 11/32" (8.73125mm) and 3/8" (9.525mm) and their respective velocities are 48.33 m/s and 43.062 m/s.
I assume they will have little or no form drag (please feel free to correct me) and therefore I am focusing on skin friction. The fluid is seawater at 20 degrees.
I tried the calculation and got a ridiculous value over ninety million ((48.33*1.9304)/ 1.004 * 10^-6). I used Re=V.L/mu. I can't move on to F=Cf(pV^2/2)S wetted with this value. Where have I gone wrong? Is the reynolds equation different for such an object?
Any information is appreciated.
Thanks
I am having trouble calculating the reynolds number for 2 spear shafts underwater. The two shafts vary in diameter and velocity. The tips are identical, stream lined to a fine point so the flow should be laminar. Both spears are 1.9304 m long. The diameters are 11/32" (8.73125mm) and 3/8" (9.525mm) and their respective velocities are 48.33 m/s and 43.062 m/s.
I assume they will have little or no form drag (please feel free to correct me) and therefore I am focusing on skin friction. The fluid is seawater at 20 degrees.
I tried the calculation and got a ridiculous value over ninety million ((48.33*1.9304)/ 1.004 * 10^-6). I used Re=V.L/mu. I can't move on to F=Cf(pV^2/2)S wetted with this value. Where have I gone wrong? Is the reynolds equation different for such an object?
Any information is appreciated.
Thanks