Abstract: An evaporator fitted on a model combustor is investigated to provide uniform circumferential gas temperature profile.It is shown that less fuel vapor exhausts from the primary holes with uniform outlet area along the evaporator,so that the lower gas temperature is behind these holes,and the more vapor from the final holes makes the gas temperature higher.The vapor flow is proportional to the outlet area as the evaporativity is 100% for the final holes.Uniform vapor flow and uniform circumferential temperature profile can be achieved with larger primary outlet holes and even final holes.