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A physical model and a mathematical model were established in order to describe and improve the“vapor-phase resistance method” of Bell and Ghaly.Considering the effect of ripples at the interface onvapor-phase resistance,a correction factor v_ι was proposed.Another factor (θ/π)β which correctsthe influence of the liquid pool along the bottom of the horizontal tube on the liquid-phase heat transfercoefficient was derived and the relationship of θ and β was correlated.The heat transfer coefficient pre-dicted by Bell’s method are approximately 10—15% lower than the experimental values if the effect ofripples on vapor-phase resistance has not been taken into account.The comparison of the predicted valuesof h_c from the modified vapor-phase resistance method with the experimental data showed a deviation of±10%.
A physical model and a mathematical model were established in order to describe and improve the “vapor-phase resistance method” of Bell and Ghaly. Cons on the effect of ripples at the interface onvapor-phase resistance, a correction factor v_ι was proposed. An additional factor (θ / π) β which correctsthe influence of the liquid pool along the bottom of the horizontal tube on the liquid-phase heat transfer coefficient was derived and the relationship of θ and β was correlated. The heat transfer coefficient pre-dicted by Bell’s method are approximately 10-15% lower than the experimental values if the effect ofripples on vapor-phase resistance has not been taken into account.The comparison of the predicted valuesof h_c from the modified vapor-phase resistance method with the experimental data showed a deviation of ± 10%.