【作者】 王欢；

【导师】 Alam Md. Mahbub；

【作者基本信息】 哈尔滨工业大学 ， 动力工程（专业学位）， 2017， 硕士

【摘要】 本文通过计算流体力学(CFD)的方法研究固定雷诺数(Re=220)下并联摆动机翼对推进力提升效果的影响。首先本文研究了在不同参数条件下(例如摆动频率StD=0.12,0.15,0.175,0.2,0.225,0.25,0.3、摆动幅度AD=1.2,1.4,1.6,1.82.0)的单个机翼(直径D=0.001 m,弦长C=6D)的尾流和受力情况。计算得到反卡门涡街的流体结构,并同时获得了水平方向的推进力。整理并制作了单个机翼的能量系数,推进力系数和推进比的图像。并且研究了机翼的摆动中心对以上各个力学系数的影响。从单个机翼的推进比图像中选取了两个具有代表性的数据组,其中一个代表低推进比系数工况,另一个代表高推进比系数工况。接着将两个机翼并联排布,在不同的机翼间隙(S*=S/D=2.5,3.1,4,5,6,8)和摆动相位差(φ=0°和180°)条件下,计算获得了能量系数,推进力系数和推进比变化趋势。从结果中发现,对于单个摆动机翼,当摆动中心在机翼前沿时,可以获得最大推进比。在摆动中心从机翼前沿移向机翼后沿的过程中,能量系数、推进力系数和推进比都会逐渐变小。在两个机翼并联排布的条件下,若两者反相摆动,则两者的推进力系数都会获得提升。但是对于单机翼的高推进比的情况,并联后推进力系数的增强幅度相对较小。反相摆动会使消耗的能量和产生的推进力都变大。在同相摆动的情况下,推进力系数相比于单个摆动机翼的推进力系数会有所减小。除此之外,同相摆动会使消耗的能量和产生的推进力都变小。当S*=2.5时,两个机翼获得最大的推进比系数提升。同时发现4种不同的流动状态,并且详细介绍了不同流态的主要特征。更多还原

【Abstract】 A numerical investigation is done to study the thrust enhancement for parallel pitching foils at fixed Reynolds number(Re = 220).Effect on thrust is examined of certain parameters like pitching frequency(StD = 0.12,0.15,0.175,0.2,0.225,0.25,0.3),pitching amplitude(AD = 1.2,1.4,1.6,1.8 2.0)and pitching center which changes from leading edge point to mid-point of the foil.The average longitudinal velocity is shown in this paper.The map of power coefficient,thrust coefficient and propulsive efficiency of single pitching foil is obtained depending on the systematic numerical study.And the effect of pitching center is numerically investigated.Two cases,i.e.low and high propulsive efficiency of single pitching foil are investigated.The effect of gap ratio(S*= S/D= 2.5,3.1,4,5,6,8)and phase-lag(φ = 0° and 180°)on the power coefficient,thrust coefficient and propulsive efficiency of two side-by-side foils are investigated systematically.The current study shows that,maximum propulsive efficiency is obtained at leading edge point.And when pitching center moves from leading edge point to trailing edge point,the thrust coefficient and power coefficient will decrease.For the parallel configuration,anti-phase pitching will amplify the propulsive efficiency regardless of the conditions of high and low propulsive efficiency for single pitching foil.But for the high propulsive efficiency of single pitching foil,the enhancement effect is smaller.In-phase oscillation has the opposite effect.Besides,the in-phase oscillation results in a drop of the thrust production and power consumption.At S* = 2.5,anti-phase condition can render the maximum propulsive efficiency enhancement.Besides,four flow patterns are obtained,and the corresponding characteristics are presented.更多还原