In order to analyze the hydrodynamic performance of the ducted propeller with high precision, this paper proposes a new method which combines Multi-Block Hybrid Mesh and Reynolds Stress Model (MBHM & RSM). The cal...In order to analyze the hydrodynamic performance of the ducted propeller with high precision, this paper proposes a new method which combines Multi-Block Hybrid Mesh and Reynolds Stress Model (MBHM & RSM). The calculation errors of MBHM & RSM and standard two-equation model (standard k-ε model) on the ducted propeller JD7704 +Ka4-55 are compared. The maximum error of the total thrust coefficient KT, the duct thrust coefficient KTN, the torque coefficient KQ and the open-water efficiency η0 of MBHM & RSM are 2.98%, 4.01%, 1.46%, and 0.89%, respectively, which are lower than those of standard k-ε model. Indeed, the pressure distribution on the propeller surfaces, the pressure and the velocity vector distribution of the flow field are also analyzed, which are consistent with the theory. It is demonstrated that MBHM & RSM on the thruster dynamics analysis are feasible. This paper provides reference in the thruster designing of underwater robot.展开更多
文摘In order to analyze the hydrodynamic performance of the ducted propeller with high precision, this paper proposes a new method which combines Multi-Block Hybrid Mesh and Reynolds Stress Model (MBHM & RSM). The calculation errors of MBHM & RSM and standard two-equation model (standard k-ε model) on the ducted propeller JD7704 +Ka4-55 are compared. The maximum error of the total thrust coefficient KT, the duct thrust coefficient KTN, the torque coefficient KQ and the open-water efficiency η0 of MBHM & RSM are 2.98%, 4.01%, 1.46%, and 0.89%, respectively, which are lower than those of standard k-ε model. Indeed, the pressure distribution on the propeller surfaces, the pressure and the velocity vector distribution of the flow field are also analyzed, which are consistent with the theory. It is demonstrated that MBHM & RSM on the thruster dynamics analysis are feasible. This paper provides reference in the thruster designing of underwater robot.
文摘电推进系统采用永磁同步电机(permanent magnet synchronous motor,PMSM)直接驱动螺旋桨为飞机提供所需的动力,由于运行工况的复杂性和强耦合性,其对动态响应和扰动抑制能力提出更高的要求。为了提高系统性能,提出一种线性/非线性自抗扰混合控制方法。在线性扩张状态观测器(linear expanding state observer,LESO)和非线性扩张状态观测器(nonlinear expanding state observer,NESO)参数整定的基础上,设计带权重系数的混合控制策略。该方法有效整合LESO和NESO的优点,通过带桨测试结果验证所提方法的可行性,为工程实践奠定理论基础。
