viv

viv function computes the viv analysis of a riser in a free flowing stream.

The viv function computes the viv analysis of a RISER in a free flowing stream. The inputs are:
u = current velocity, ft/s; nu = kinematic viscosity, ft^2/s; od = pipe OD, ft; id = pipe ID, ft; df = density of the internal fluid, lb/ft^3; wd = water depth, ft; ag = riser air gap, ft; whh = well head height, ft; dm = density of the pipe material, lb/ft^3; e = elastics modulus of the pipe material, ksf.
The OUTPUTS are: Reynolds Number; Modal Frequency; viv lock in mode; viv Frequency; viv Amplitude; Lateral Deflection due to viv; viv Stress; Vibration cycles per day.