竖轴水轮机瞬态启动性能分析

Transient starting performance analysis of vertical axis tidal turbine

竖轴水轮机在瞬态启动过程中旋转角速度随时间不断变化,为了解决常规的定转速数值方法不能模拟上述过程的问题,利用开源软件OpenFOAM中SixDoFRigidBodyMotion模块的耦合算法实现了竖轴水轮机的瞬态启动过程.通过CFD(计算流体力学)方法着重分析水轮机转动惯量和阻尼值对启动过程的影响,发现两叶片竖轴水轮机的最佳启动位置角约为110°.通过对比须设置阻尼值的耦合模拟方法和定转速模拟方法,发现两者均可得出水轮机功率系数随转速变化的规律,而前者更接近水轮机的真实运转工况.

Due to the angular velocity varies with time in the transient starting process of vertical axis tidal turbine,and the traditional fixed rotational velocity numerical method can′t simulate such process,a coupling algorithm in the SixDoFRigidBodyMotion module of the open source software OpenFOAM was used to realize the transient starting process of the vertical axis turbine.The influence of the turbine′s moment of inertia and damping value on the starting process of vertical axis turbine was analyzed by CFD（computational fluid dynamics）method,and a conclusion that the optimum start-up position angle of the two-blade vertical axis turbine is in the vicinity of 110°was obtained.Moreover,by comparing the coupling simulation method which needs to set damping value and the fixed rotational velocity simulation method,it was found that both could obtain the variation law of the power coefficient of turbine with the rotating velocity,while the former method contains more research value as it′s closer to the real operation of turbine.