The Experts below are selected from a list of 7530 Experts worldwide ranked by ideXlab platform
Xianwu Luo - One of the best experts on this subject based on the ideXlab platform.
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investigation on the effect of forward skew angle blade on the hump characteristic in a mixed flow Pump using modified partially averaged navier stokes model
Renewable Energy, 2021Co-Authors: Akihiro Ikuta, Yining Chen, Kazuyoshi Miyagawa, Xianwu LuoAbstract:Abstract A mixed flow Pump is regarded as an important power facility in the hydropower field for renewable energy. Pump Impeller design shows a great attempt to alleviate the hump characteristic and suppress the severe pressure fluctuations as the mixed flow Pumps operate under part-load conditions. In this respect, an advanced turbulence model, i.e., modified SST k-ω partially averaged Navier-Stokes (MSST PANS) model, was adopted to numerically investigate the effect of forward skew angle blade on the hump characteristic using different Impeller blades. Both experimental and numerical results indicate that the Pump with forward skew angle blade shifts the hump region to the deeper part-load region. In the Pump Impeller with the forward skew angle blades, a synchronous stall cell is observed near the blade leading edge and near the hub side, while typical rotating stall cell evolution is observed in the conventional Pump Impeller. Analysis on the blade loading also indicates that under the unstable condition, the forward skew angle blade could switch the mid-loaded distribution to the fore-loaded distribution. Finally, the low frequency pressure fluctuations induced by the rotating stall cell evolution could be also eliminated successfully as the forward skew angle Impeller blades are adopted.
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multi objective optimization of a mixed flow Pump Impeller using modified nsga ii algorithm
Science China-technological Sciences, 2015Co-Authors: Renfang Huang, Xianwu Luo, Peng Wang, Zhihong Zhai, Jiajian ZhouAbstract:In order to maintain a uniform distribution of pareto-front solutions, a modified NSGA-II algorithm coupled with a dynamic crowding distance (DCD) method is proposed for the multi-objective optimization of a mixed-flow Pump Impeller. With the Pump meridional section fixed, ten variables along the shroud and hub are selected to control the blade load by using a three-dimensional inverse design method. Hydraulic efficiency, along with Impeller head, is applied as an optimization objective; and a radial basis neural network (RBNN) is adopted to approximate the objective function with 82 training samples. Local sensitivity analysis shows that decision variables have different impacts on the optimization objectives. Instead of randomly selecting one solution to implement, a technique for ordering preferences by similarity to ideal solution (TOPSIS) is introduced to select the best compromise solution (BCS) from pareto-front sets. The proposed method is applied to optimize the baseline model, i.e. a mixed- flow waterjet Pump whose specific speed is 508 min-1·m3s-1·m. The performance of the waterjet Pump was experimentally tested. Compared with the baseline model, the optimized Impeller has a better hydraulic efficiency of 92% as well as a higher Impeller head at the design operation point. Furthermore, the off-design performance is improved with a wider high- efficiency operation range. After optimization, velocity gradients on the suction surface are smoother and flow separations are eliminated at the blade inlet part. Thus, the authors believe the proposed method is helpful for optimizing the mixed-flow Pumps.
Akihiro Ikuta - One of the best experts on this subject based on the ideXlab platform.
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investigation on the effect of forward skew angle blade on the hump characteristic in a mixed flow Pump using modified partially averaged navier stokes model
Renewable Energy, 2021Co-Authors: Akihiro Ikuta, Yining Chen, Kazuyoshi Miyagawa, Xianwu LuoAbstract:Abstract A mixed flow Pump is regarded as an important power facility in the hydropower field for renewable energy. Pump Impeller design shows a great attempt to alleviate the hump characteristic and suppress the severe pressure fluctuations as the mixed flow Pumps operate under part-load conditions. In this respect, an advanced turbulence model, i.e., modified SST k-ω partially averaged Navier-Stokes (MSST PANS) model, was adopted to numerically investigate the effect of forward skew angle blade on the hump characteristic using different Impeller blades. Both experimental and numerical results indicate that the Pump with forward skew angle blade shifts the hump region to the deeper part-load region. In the Pump Impeller with the forward skew angle blades, a synchronous stall cell is observed near the blade leading edge and near the hub side, while typical rotating stall cell evolution is observed in the conventional Pump Impeller. Analysis on the blade loading also indicates that under the unstable condition, the forward skew angle blade could switch the mid-loaded distribution to the fore-loaded distribution. Finally, the low frequency pressure fluctuations induced by the rotating stall cell evolution could be also eliminated successfully as the forward skew angle Impeller blades are adopted.
Hiroshi Tsukamoto - One of the best experts on this subject based on the ideXlab platform.
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unsteady hydrodynamic forces due to rotor stator interaction on a diffuser Pump with identical number of vanes on the Impeller and diffuser
Journal of Fluids Engineering-transactions of The Asme, 2005Co-Authors: M Zhang, Hiroshi TsukamotoAbstract:Experimental and computational study was developed for unsteady hydrodynamic forces on a diffuser Pump Impeller excited by the interaction between the Impeller and the vaned diffuser with the same number of vanes as Impeller. Unsteady flow calculations are made using commercially available CFD software, CFX-TASCflow, as well as the two-dimensional vortex method. Calculated pressure and fluid forces on the Impeller show good agreement with measured ones. It has been demonstrated that the fluid forces on the Impeller with the same number of vanes as the vaned diffuser are smaller compared with other combinations of vane numbers. However, the pressure fluctuations are found to be greater than other cases.
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numerical analysis of unsteady hydrodynamic forces on a diffuser Pump Impeller due to rotor stator interaction
ASME 2002 Joint U.S.-European Fluids Engineering Division Conference, 2002Co-Authors: M Zhang, H Wang, Hiroshi TsukamotoAbstract:The 2-D vortex method and the commercially available CFD software are applied to calculate unsteady hydrodynamic forces on a diffuser Pump Impeller and the pressure fluctuations caused by the interaction between the Impeller and the diffuser vanes. Calculated pressure and fluid forces on the Impeller are compared with measured ones. The numerical analysis yields fairly accurate predictions of the fluid forces and the pressure fluctuations in diffuser passages and the pipe systems. It has been demonstrated that the fluid forces caused by the interaction between the rotor and stator vanes are small when the number of vanes on Impeller and diffuser is identical. In this case, however, the local pressure fluctuations are larger in diffuser passages and the pipe systems.© 2002 ASME
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pressure fluctuation downstream of diffuser Pump Impeller
Transactions of the Japan Society of Mechanical Engineers. B, 1995Co-Authors: Hiroshi Tsukamoto, Yuji Nagai, Hiroki Fukuno, Nobunari Hamafuku, Tomoyoshi OkamuraAbstract:Instantaneous pressures were measured on the casing wall of a guide vane passage and volute casing of a diffuser Pump in order to investigate the interaction between Impeller blades and diffuser vanes. The pressure fluctuations were discussed using statistical analysis as well as the ensemble-averaging technique. Frequency spectra of unsteady pressure data show that the dominant frequencies are the Impeller blade passage frequency and its higher harmonics. Moreover, the ensemble-averaged pressure data show the spatial distribution of unsteady pressures, which illustrates the rotation of the circumferential pressure mode due to rotor-stator interaction.
Kazuyoshi Miyagawa - One of the best experts on this subject based on the ideXlab platform.
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investigation on the effect of forward skew angle blade on the hump characteristic in a mixed flow Pump using modified partially averaged navier stokes model
Renewable Energy, 2021Co-Authors: Akihiro Ikuta, Yining Chen, Kazuyoshi Miyagawa, Xianwu LuoAbstract:Abstract A mixed flow Pump is regarded as an important power facility in the hydropower field for renewable energy. Pump Impeller design shows a great attempt to alleviate the hump characteristic and suppress the severe pressure fluctuations as the mixed flow Pumps operate under part-load conditions. In this respect, an advanced turbulence model, i.e., modified SST k-ω partially averaged Navier-Stokes (MSST PANS) model, was adopted to numerically investigate the effect of forward skew angle blade on the hump characteristic using different Impeller blades. Both experimental and numerical results indicate that the Pump with forward skew angle blade shifts the hump region to the deeper part-load region. In the Pump Impeller with the forward skew angle blades, a synchronous stall cell is observed near the blade leading edge and near the hub side, while typical rotating stall cell evolution is observed in the conventional Pump Impeller. Analysis on the blade loading also indicates that under the unstable condition, the forward skew angle blade could switch the mid-loaded distribution to the fore-loaded distribution. Finally, the low frequency pressure fluctuations induced by the rotating stall cell evolution could be also eliminated successfully as the forward skew angle Impeller blades are adopted.
Yining Chen - One of the best experts on this subject based on the ideXlab platform.
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investigation on the effect of forward skew angle blade on the hump characteristic in a mixed flow Pump using modified partially averaged navier stokes model
Renewable Energy, 2021Co-Authors: Akihiro Ikuta, Yining Chen, Kazuyoshi Miyagawa, Xianwu LuoAbstract:Abstract A mixed flow Pump is regarded as an important power facility in the hydropower field for renewable energy. Pump Impeller design shows a great attempt to alleviate the hump characteristic and suppress the severe pressure fluctuations as the mixed flow Pumps operate under part-load conditions. In this respect, an advanced turbulence model, i.e., modified SST k-ω partially averaged Navier-Stokes (MSST PANS) model, was adopted to numerically investigate the effect of forward skew angle blade on the hump characteristic using different Impeller blades. Both experimental and numerical results indicate that the Pump with forward skew angle blade shifts the hump region to the deeper part-load region. In the Pump Impeller with the forward skew angle blades, a synchronous stall cell is observed near the blade leading edge and near the hub side, while typical rotating stall cell evolution is observed in the conventional Pump Impeller. Analysis on the blade loading also indicates that under the unstable condition, the forward skew angle blade could switch the mid-loaded distribution to the fore-loaded distribution. Finally, the low frequency pressure fluctuations induced by the rotating stall cell evolution could be also eliminated successfully as the forward skew angle Impeller blades are adopted.
