Yuqin Wang^1,2,3,*, Luxiang Zhou³, Mengle Han¹, Lixiang Shen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2215-2228, 2023, DOI:10.32604/fdmp.2023.027188

Abstract The main structural parameters of the IR100-80-100A type chemical centrifugal pump have been optimized by means of an orthogonal test approach. The centrifugal pump has been modeled using the CFturbo software, and 16 sets of orthogonal-test schemes have been defined on the basis of 4 parameters, namely, the blade number, blade outlet angle, impeller outlet diameter, and impeller outlet width. Such analysis has been used to determine the influence of each index parameter on the pump working efficiency and identify a set of optimal combinations of such parameters. The internal flow field in the centrifugal pump has been simulated by… More > Graphic Abstract

Huanwei Xu^*, Wenzhang Wei, Hanjin He, Xuerui Yang

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.1, pp. 173-199, 2022, DOI:10.32604/cmes.2022.019424

Abstract The surrogate model technology has a good performance in solving black-box optimization problems, which is widely used in multi-domain engineering optimization problems. The adaptive surrogate model is the mainstream research direction of surrogate model technology, which can realize model fitting and global optimization of engineering problems by infilling criteria. Based on the idea of the adaptive surrogate model, this paper proposes an efficient global optimization algorithm based on the local remodeling method (EGO-LR), which aims at improving the accuracy and optimization efficiency of the model. The proposed algorithm firstly constructs the expectation improvement (EI) function in the local area and… More >

Ting Zhang¹, Denghao Wu^1,2,*, Shijun Qiu², Peijian Zhou¹, Yun Ren³, Jiegang Mou¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1349-1361, 2022, DOI:10.32604/fdmp.2022.019617

Abstract Stall phenomena increase the complexity of the internal flow in centrifugal pump impellers. In order to tackle this problem, in the present work, a large eddy simulation (LES) approach is applied to determine the characteristics of these unstable flows. Moreover, a vorticity identification method is used to characterize quantitatively the vortex position inside the impeller and its influencing area. By comparing the outcomes of the numerical simulations and experimental results provided by a Particle Image Velocimetry (PIV) technique, it is shown that an apparent “alternating stall” phenomenon exists inside the impeller when relatively small flow rate conditions are considered. The… More >

Xiaorui Cheng^1,2,*, Xiang Liu¹, Boru Lv¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.1, pp. 93-107, 2022, DOI:10.32604/fdmp.2022.017566

Abstract An AP1000 nuclear reactor coolant pump is considered to assess the influence of the Impeller/Guide vane clearance on the performances of this type of pumps. Experiments and numerical simulations relying on an unidirectional fluid-solid coupling approach are used to investigate the problem (stress, strain and mode of the rotor). The results reveal the relationship existing between the hydraulic performance of the nuclear reactor coolant pump and the clearance ratio. The effect of clearance ratio on the maximum equivalent stress on the back surface of the impeller blade is greater than that on the working surface (the maximum equivalent stress on… More >

Ravindra Birajdar^1,*, Appasaheb Keste², Shravan Gawande²

Sound & Vibration, Vol.55, No.4, pp. 305-327, 2021, DOI:10.32604/sv.2021.017000

Abstract The objective of the study is to find the tolerance on vane pitch dimensions of a Vertical Turbine (VT) pump impeller. For this purpose, the study is divided into two parts viz. to find the critical hydraulic eccentricity of a VT pump impeller by way of numerical simulations and design of experiments to find the vane pitch tolerance using critical hydraulic eccentricity. The effect of impeller vane pitch deviations on hydraulic unbalance is examined for a vertical turbine pump using Design of Experiments (DOE). A suitable orthogonal matrix has been selected with vane pitch at different axial locations of an… More >

Jinguang Yang, Feng Zhao, Min Zhang^*, Yan Liu, Xiaofang Wang

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.3, pp. 935-953, 2021, DOI:10.32604/cmes.2021.014176

Abstract For a radial inflow turbine (RIT), leakage flow in impeller backface cavity has critical impacts on aerodynamic performance of the RIT and axial force acting on the RIT impeller. In order to control this leakage flow, different types of labyrinth seals are numerically studied in this paper based on a supercritical carbon dioxide (S-CO₂) RIT. The effects of seal clearance and cavity outlet pressure are first analyzed, and the impacts of seal design parameters, including height, number and shape of seal teeth, are evaluated. Results indicate that adding labyrinth seal can improve cavity pressure and hence adequately inhibits leakage flow.… More >

Weimin Wu, Chuande Zhou^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 883-901, 2020, DOI:10.32604/fdmp.2020.010407

Abstract The behavior of the tip wake of a wind turbine is one of the hot issues in the wind power field. This problem can partially be tackled using Computational Fluid Dynamics (CFD). However, this approach lacks the ability to provide insights into the spatial structure of important high-order flows. Therefore, with the horizontal axis wind turbine as the main focus, in this work, firstly, we conduct CFD simulations of the wind turbine in order to obtain a data-driven basis relating to multiple working conditions for further analysis. Then, these data are studied using an extended Proper Orthogonal Decomposition (POD) algorithm.… More >

R. A. Tough^1,2, A. M. Tousi², J. Ghaffari²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.14, No.1, pp. 1-22, 2010, DOI:10.3970/icces.2010.014.001

Abstract In this paper, micro-turbine centrifugal impeller with three different blade angles was investigated by using Computational Fluid Dynamics (CFD) method. The other basic geometric parameters are held constant. The influence of the blade angles change on the observed values was determined from numerical solution of the flow in the impeller with help of the FLUENT software. The numerical simulation focused on the air flow from compressor impeller inlet to exit, and the performance of impeller is predicted. The numerical solution was performed for original impeller geometry and for two other cases, in which blade inlet angle and backward sweep was… More >

K. Kakuda¹, T. Nagashima¹, Y. Hayashi¹, S. Obara¹, J. Toyotani¹, S. Miura², N. Katsurada³, S. Higuchi³, S. Matsuda³

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.5, pp. 363-376, 2013, DOI:10.3970/cmes.2013.093.363

Abstract The application of a GPU-based particle method to three-dimensional incompressible viscous fluid flow problems is presented. The particle approach is based on the MPS (Moving Particle Semi-implicit) scheme using logarithmic weighting function to stabilize the spurious oscillatory solutions for solving the Poisson equation with respect to the pressure fields by using GPU-based SCG (Scaled Conjugate Gradient) method. Numerical results demonstrate the workability and the validity of the present approach through the dam-breaking flow problem and flow behavior in a liquid ring pump with rotating impeller blades. More >

K. Kakuda¹, Y. Ushiyama¹, S. Obara¹, J. Toyotani¹, S. Matsuda², H.Tanaka², K. Katagiri²

CMES-Computer Modeling in Engineering & Sciences, Vol.66, No.3, pp. 215-226, 2010, DOI:10.3970/cmes.2010.066.215

Abstract The application of the MPS (Moving Particle Semi-implicit) scheme to incompressible viscous fluid flow problem in the liquid ring vacuum pump with rotating impeller is presented. The rotating impeller in the pump is attached to a center hub and located in off-set from the center of a cylindrical body. For such flow problem there are some interesting phenomena including the formation of the liquid ring by rotating impeller, the interface dynamics between gas and liquid, and so forth. The MPS scheme is widely utilized as a particle strategy for the free surface flow, the problem of moving boundary, and multi-physics/multi-scale… More >