多桨船舶自航因子数值预报

以某四桨水面船舶为研究对象，基于RANS方法和滑移网格技术，建立船、附体和螺旋桨整体计算模型，并运用小范围改变螺旋桨转速的方法和前后桨分别计算的方法预报该船的自航因子。结果表明：四桨船舶内、外桨的自航因子并不相等，内后桨的实效伴流分数和推力减额分数均比外前桨的大；提出的方法计算结果可靠，能够体现四桨船舶自航因子的差异性，并且符合推力减额与伴流关系的一般规律，可为多桨船舶的自航试验提供依据。

Prediction of Self-Propulsion Parameters for Multi-Propeller Ships

In this paper, a four-propeller surface ship is studied and an integral mathematic model including the hull appendage and propellers is established. Using a RANS solver and moving grids,the self-propulsion factors are predicted by gradually modifying the rotation speed of the propeller and by respectively calculating the propeller features. The result shows that the self-propulsion factors of the inner propeller differs from those of the outer propeller. The wake fraction and thrust deduction fraction of the inner propeller is bigger than the outer propeller＇s. In brief, the differences among four-propeller ship self-propulsion factors can be observed and are seen to fit the ordinary relation of thrust deduction and wake, which validates the reliability of the new proposed method and provides the basis for future self-propulsion tests of multi-propeller ships.