In a supersonic flow of pure vapour in a convergent-divergent nozzle, sometimes nucleation phenomena and subsequently condensation of water vapour is occurred. The nucleation processes cause the formation of small water droplets and therefore the fluid becomes a two-phase flow. This growing droplets release the latent heats to the vapour flow and this heat addition to the supersonic flow causes a pressure rise which is called as a condensation shock. This condensation shock causes instability of the flow that is an unfavorable event. On the other hand these formed droplets strike to the walls strongly and make very serious mechanical damages. In the following of the previous researches of authors this paper considers some new approaches for decreasing the nucleation rate and suppressing the intensity of condensation shock. The influences of volumetric heat transfer to the supersonic flow of pure water vapour in a convergent-divergent nozzle are analytically considered and via this technique a new method is suggested to achieve mentioned purpose. The results show that suitable volumetric heat transfer to the convergent part of the steam flow suppressing the degree of supercooling and subsequently the nucleation rate. Consequently the released latent heat to the flow is abated which causing the control of the condensation shock. As a result of suppression of nucleation rate, the formed droplets in the vapour and their mechanical damages are decreased. Also diminution of condensation decreases the irreversibleness and the internal heat transferring. Generally it is concluded that the heat transfer to the convergent section of a Laval nozzle, damping the condensation shock, stable the flow, decreasing the suspended droplets and their following damages, and finally reducing the flow losses.

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