Design Optimization of Forward-Curved Blades Centrifugal Fan With Response Surface Method

Author(s):  
Seoung-Jin Seo ◽  
Kwang-Yong Kim

This paper presents the response surface optimization method using three-dimensional Navier-Stokes analysis to optimize the shape of a forward-curved blades centrifugal fan. For numerical analysis, Reynolds-averaged Navier-Stokes equations with k-ε turbulence model are discretized with finite volume approximations. In order to reduce huge computing time due to a large number of blades in forward-curved blades centrifugal fan, the flow inside of the fan is regarded as steady flow by introducing the impeller force models. Three geometric variables, i.e., location of cut off, radius of cut off, and width of impeller, and one operating variable, i.e., flow rate, were selected as design variables. As a main result of the optimization, the efficiency was successfully improved. And, optimum design flow rate was found by using flow rate as one of design variables. It was found that the optimization process provides reliable design of this kind of fans with reasonable computing time.

2004 ◽  
Vol 126 (5) ◽  
pp. 735-742 ◽  
Author(s):  
Kwang-Yong Kim ◽  
Seoung-Jin Seo

In this paper, the response surface method using a three-dimensional Navier-Stokes analysis to optimize the shape of a forward-curved-blade centrifugal fan is described. For the numerical analysis, Reynolds-averaged Navier-Stokes equations with the standard k-ε turbulence model are discretized with finite volume approximations. The SIMPLEC algorithm is used as a velocity–pressure correction procedure. In order to reduce the huge computing time due to a large number of blades in forward-curved-blade centrifugal fan, the flow inside of the fan is regarded as steady flow by introducing the impeller force models. Four design variables, i.e., location of cutoff, radius of cutoff, expansion angle of scroll, and width of impeller, were selected to optimize the shapes of scroll and blades. Data points for response evaluations were selected by D-optimal design, and a linear programming method was used for the optimization on the response surface. As a main result of the optimization, the efficiency was successfully improved. Effects of the relative size of the inactive zone at the exit of impeller and momentum fluxes of the flow in scroll on efficiency were further discussed. It was found that the optimization process provides a reliable design of this kind of fan with reasonable computing time.


Author(s):  
Chan-Sol Ahn ◽  
Kwang-Yong Kim

Design optimization of a transonic compressor rotor (NASA rotor 37) using the response surface method and three-dimensional Navier-Stokes analysis has been carried out in this work. The Baldwin-Lomax turbulence model was used in the flow analysis. Three design variables were selected to optimize the stacking line of the blade. Data points for response evaluations were selected by D-optimal design, and linear programming method was used for the optimization on the response surface. As a main result of the optimization, adiabatic efficiency was successfully improved. It was found that the optimization process provides reliable design of a turbomachinery blade with reasonable computing time.


Author(s):  
C-S Ahn ◽  
K-Y Kim

Design optimization of a transonic compressor rotor (NASA rotor 37) using the response surface method (RSM) and three-dimensional Navier-Stokes analysis has been carried out in this work. The Baldwin—Lomax turbulence model was used in the flow analysis. Three design variables were selected to optimize the stacking line of the blade. Data points for response evaluations were selected by D-optimal i design, and a linear programming method was used to optimize the response surface. As a main result of the optimization, adiabatic efficiency was successfully improved. It was found that the optimization process provides reliable design of a turbomachinery blade with reasonable computing time.


Author(s):  
Man-Woong Heo ◽  
Jin-Hyuk Kim ◽  
Kwang-Yong Kim

AbstractMulti-objective optimization of a centrifugal fan with additionally installed splitter blades was performed to simultaneously maximize the efficiency and pressure rise using three-dimensional Reynolds-averaged Navier-Stokes equations and hybrid multi-objective evolutionary algorithm. Two design variables defining the location of splitter, and the height ratio between inlet and outlet of impeller were selected for the optimization. In addition, the aerodynamic characteristics of the centrifugal fan were investigated with the variation of design variables in the design space. Latin hypercube sampling was used to select the training points, and response surface approximation models were constructed as surrogate models of the objective functions. With the optimization, both the efficiency and pressure rise of the centrifugal fan with splitter blades were improved considerably compared to the reference model.


Author(s):  
A. F. Tabak ◽  
A. Solak ◽  
E. Y. Erdem ◽  
C. Akcan ◽  
S. Yesilyurt

It is expected that chemical, biological and environmental applications of microdevices will increase with new developments in micromachining techniques. In this work, a micropump design that utilizes passive valves and an actuated diaphragm is presented. The flow rate is controlled by the deflection and the frequency of the diaphragm’s displacement. Passive valves are used for directing the flow. Poiseuille flow analogy is used to generate the equivalent pressure drop and flow rate via modifying the viscosity in the valve-channel in order to replace the variation of the channel width due to valve movement. Overall flow in the micropump is governed by three-dimensional time-dependent Navier Stokes equations. Deformation of the domain due to moving boundaries that coincide with the diaphragm motion is handled with the arbitrary Lagrangian-Eulerian method. Flow rate, hydraulic power and the efficiency of the micropump are obtained with respect to driving frequency and displacement of the diaphragm.


Author(s):  
Choon-Man Jang ◽  
Sang-Yoon Lee ◽  
Sang-Ho Yang

Shape optimization in the design of turbomachinery based on the three-dimensional flow analysis has been developed remarkably in recent years with the rapid enhancement of computational power. In the present study, optimal design of a centrifugal fan installed in refuse collecting system has been performed using response surface method and three-dimensional Navier-Stokes analysis to increase fan efficiency. The centrifugal fan is used to increase suction pressure for the moving of a waste through the pipe line of the system. Two design variables, which are used to define the shape of an inlet guide, are introduced to increase the efficiency of the fan. In the shape optimization using the response surface method, data points for response evaluations are selected, and linear programming method is used for an optimization on a response surface. To analyze three-dimensional flow field in the centrifugal fan, general analysis code, CFX, is employed in the present work: SST turbulence model is employed to estimate the eddy viscosity. Unstructured grids are used to represent a composite grid system including blade, casing and inlet guide. Throughout the shape optimization of a centrifugal fan, the fan efficiency is successfully increased by decreasing local losses in the blade passage. The result of shape optimization shows that the efficiency of the optimized shape at the design flow condition is enhanced by 1.42% based on the reference fan. It is found that recirculation flow region of optimum one is relatively small compared to the reference one. The reduction of recirculation region can be decreased the shaft power of an impeller, thus it can be increased the efficiency of the fan.


Author(s):  
Man-Woong Heo ◽  
Jin-Hyuk Kim ◽  
Kyung-Hun Cha ◽  
Kwang-Yong Kim

Aerodynamic Performance of a centrifugal fan with additionally installed splitter blades in the impeller has been investigated numerically using three-dimensional Reynolds-averaged Navier-Stokes equations. The shear stress transport turbulence model and hexahedral grids system were used to analyze the flow in the centrifugal fan. From results of the flow analysis, considerable energy loss by flow separation was observed in the blade passages. Splitter blades were applied between the main blades to reduce the loss and enhance fan performance. The chord length ratio of splitter to main blade, the angle between splitter and main blade, and the height ratio of outlet and inlet of impeller were selected as the geometric parameters, and their effects on the aerodynamic performance of the centrifugal fan have been investigated. The performance of the centrifugal fan with added splitter blades was improved conspicuously compared to the centrifugal fan without splitter blades. It was found that the installation of splitter blades in the impeller is effective to improve the aerodynamic performance of a centrifugal fan by reducing the flow separation generated between main blades in the impeller.


Author(s):  
Liming Song ◽  
Zhenping Feng ◽  
Jun Li

A new optimization method named as Adaptive Range Differential Evolution (ARDE) is proposed and developed for the turbine stage design. The mathematical tests are used to demonstrate the optimization performance of the present ARDE through compared with the Simple Genetic Algorithms (SGA) and the Differential Evolution (DE). Combined with the ARDE, surface modeling method and Navier-Stokes solver, a low aspect ratio transonic turbine stage is optimized, with 28 design variables in total, for the maximization of the isentropic efficiency. The optimization design of this case is performed on the cluster parallel Personal Computers. The optimal design turbine stage shows a better aerodynamic performance than that of the reference design while meeting the strength requirement. The robustness and reliability of the presented ARDE for the turbomachinery optimization design are also illustrated.


2012 ◽  
Vol 468-471 ◽  
pp. 2231-2234
Author(s):  
Feng Gao ◽  
Wei Yan Zhong

Numerical simulation of the three-dimensional steady and unsteady turbulent flow in the whole flow field of a multi-blade centrifugal fan is performed. Unstructured grids is used to discrete the computational domain. Pressure boundary conditions are specified to the inlet and the outlet. The SIMPLE algorithm in conjunction with the RNG k-ε turbulent model is used to solve the three-dimensional Navier-Stokes equations. The moving reference frame is adopted to transfer data between the interfaces of the rotating field and the stationary field. Based on the calculation of the inner-flow in the fan, the pressure pulsation of some important monitoring points and the aerodynamic noise distribution, banding together experiment data were farther analyzed The simulation results are of important significance to the optimal design and noise control of the fan.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6210
Author(s):  
Martina Bašić ◽  
Branko Blagojević ◽  
Chong Peng ◽  
Josip Bašić

This paper introduces a novel meshless and Lagrangian approach for simulating non-Newtonian flows, named Lagrangian Differencing Dynamics (LDD). Second-order-consistent spatial operators are used to directly discretize and solve generalized Navier–Stokes equations in a strong formulation. The solution is obtained using a split-step scheme, i.e., by decoupling the solutions of the pressure and velocity. The pressure is obtained by solving a Poisson equation, and the velocity is solved in a semi-implicit formulation. The matrix-free solution to the equations, and Lagrangian advection of mesh-free nodes allowed for a fully parallelized implementation on the CPU and GPU, which ensured an affordable computing time and large time steps. A set of four benchmarks are presented to demonstrate the robustness and accuracy of the proposed formulation. The tested two- and three-dimensional simulations used Power Law, Casson and Bingham models. An Abram slump test and a dam break test were performed using the Bingham model, yielding visual and numerical results in accordance with the experimental data. A square lid-driven cavity was tested using the Casson model, while the Power Law model was used for a skewed lid-driven cavity test. The simulation results of the lid-driven cavity tests are in good agreement with velocity profiles and stream lines of published reports. A fully implicit scheme will be introduced in future work. As the method precisely reproduces the pressure field, non-Newtonian models that strongly depend on the pressure will be validated.


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