% Fully developed laminar pipe flow with constant wall heat flux. 
function [h, NuL, f, ReD] = LamPipeNuH(um,D,L,mat,Tm)
  [Z, ReD, Pr, km] = InvGz(um,D,L,mat,Tm);   
  if max(ReD) > 2300 warning = 'LamPipeNuH: ReD > 2300'
  end
  f   = 64./ReD;                            % Table 11-1
  NuL = GrtzNuL('H',64,4.36,Z);             
  h   = NuL.*km./D;
end
