% Forced convection from a sphere
function [h, NuD, ReD] = SphereNuT(U,D,mat,Ts,Tinf)
  [ReD,Pr,kf] = Re(U,D,mat,Tinf);                             
  mf   = prop('mu',mat,Tinf);                                 % at fluid temperature
  ms   = prop('mu',mat,Ts);                                   % at surface temperature
  if min(ReD) < 3.5   warning = 'SphereNuT: ReD < 3.5'
  end
  if max(ReD) > 7.6e4 warning = 'SphereNuT: ReD > 7.6e4'
  end
  % published limit of Pr>=0.71 has been changed to 0.6 below
  if min(Pr) < 0.6 warning = 'SphereNuT: Pr < 0.6'
  end
  if max(Pr) > 380 warning = 'SphereNuT: Pr > 380'
  end
  % published limit of mf/ms >=1 has been changed to 0.8 below
  if min(mf./ms) < 0.8 warning = 'SphereNuT: mf/ms < 0.8'
  end
  if max(mf./ms) > 3.2 warning = 'SphereNuT: mf/ms > 3.2'
  end
  NuD  = 2+(0.4*ReD.^0.5+0.06*ReD.^(2/3)).*Pr.^0.4.*(mf./ms).^0.25; 
  h    = NuD.*kf./D;                                                
end
