function [f, dfdX] = mdot(desvar, lb, ub, Tlim)

dvscal = 0.5*(ub - lb);

Ucool = lb(1) + (desvar(1)+1)*dvscal(1); % m/sec
h     = lb(2) + (desvar(2)+1)*dvscal(2); % Height of liner cooling hole entrance in meters


f       = Ucool*h;
dfdX(1) =       h*dvscal(1);
dfdX(2) = Ucool  *dvscal(2);

