In this work, the vortex shedding behind circular cylinder under heavy rain effects is simulated numerically; with the benchmark cases are first validated. The heavy rain effect is activated by using two-phase flow approach’s Discrete Phase Model and surface roughness mechanism, which has been proved to be successful earlier in our airfoil cases. Then high Reynolds number grooved surface cable is further investigated and the explanation of physical processes for cable rain effects at different Reynolds number is fulfilled. The information gained here will be useful for the general aviation industrial application.