The required fraction of the surface area for cooling the liquid phase is approximately 15%. However the number of naturally submerged tuber ,caculated balanced pressure drop modle, is 290,which means that 22% of the surface is submerged by the liquid phase.you can re-run the case with an input value area fraction submerged less than 22% to bring the input and required values of the submerged surface into agreement 这是什么意思