function rt=f_buoyantmo(rhoS, rhoF, d, g, CD)

  %* f_buoyantmo(rhoS, rhoF, d, g, CD)  
%  computes maximum rise rate of a sphere due to buoyancy WITH turbulence
%
%  input variables:
%  rhoS:	density of spherical object, kg/m^3
%  rhoF:    density of fluid. kg/m^3
%  d:           diameter of sphere, m
%  g:		acceleration due to gravity at this location, m/s
%  CD:      drag coefficient for sphere at appropriate Re
%
%  return variable:
%  rt(1):		rise speed  m/s

rt = sign(rhoS-rhoF)*sqrt(4/3 * d * g * abs(rhoS-rhoF) / CD / rhoF);