Suppression of Leading Edge Separation and Tip Leakage Flow in a Transonic Centrifugal Compressor Impeller Using an Inverse Design Method Based on Meridional Viscous Flow Analysis

2020 ◽  
Vol 2020 (0) ◽  
pp. OS07-06
Author(s):  
Shu TAKANO ◽  
Kaito MANABE ◽  
Sasuga ITO ◽  
Masato FURUKAWA ◽  
Isao TOMITA ◽  
...  
Keyword(s):  
Design Method ◽  
Flow Analysis ◽  
Leading Edge ◽  
Inverse Design ◽  
Tip Leakage Flow ◽  
Tip Leakage ◽  
Transonic Centrifugal Compressor ◽  
Compressor Impeller ◽  
Inverse Design Method ◽  
Edge Separation

Investigation of an Inversely Designed Centrifugal Compressor Stage: Part 1 — Design and Numerical Verification

2003 ◽  
Author(s):  
M. Zangeneh ◽  
M. Schleer ◽  
F. Plo̸ger ◽  
S. S. Hong ◽  
C. Roduner ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Design Method ◽  
Leading Edge ◽  
Inverse Design ◽  
Numerical Verification ◽  
Appreciable Effect ◽  
Tip Leakage Flow ◽  
Flow Angle ◽  
Compressor Impeller ◽  
Blade Geometry

In this paper the 3D inverse design code TURBOdesign-1 is applied to the design of the blade geometry of a centrifugal compressor impeller with splitter blades. In the design of conventional impellers the splitter blades normally have the same geometry as the full blades and are placed at mid-pitch location between the two full blades, which can usually result in a mis-match between the flow angle and blade angles at the splitter leading edge. In the inverse design method the splitter and full blade geometry is computed independently for a specified distribution of blade loading on the splitter and full blades. In this paper the basic design methodology is outlined and then the flow in the conventional and inverse designed impeller is compared in detail by using CFD code TASCflow. The CFD results confirm that the inverse design impeller has a more uniform exit flow, better control of tip leakage flow and higher efficiency than the conventional impeller. The results also show that the shape of the trailing edge geometry has a very appreciable effect on the impeller Euler head and this must be accurately modeled in all CFD computations to ensure closer match between CFD and experimental results. Detailed measurements are presented in part 2 of the paper.

An experience-independent inverse design optimization method of compressor cascade airfoil

2019 ◽  
Vol 233 (4) ◽  
pp. 431-442 ◽  
Author(s):  
Yujie Zhu ◽  
Yaping Ju ◽  
Chuhua Zhang
Keyword(s):  
Design Optimization ◽  
Design Method ◽  
Three Dimensional ◽  
Optimal Solution ◽  
Leading Edge ◽  
Optimization Method ◽  
Inverse Design ◽  
Compressor Cascade ◽  
Suction Surface ◽  
Inverse Design Method

Most of the inverse design methods of turbomachinery experience the shortcoming where the target aerodynamic parameters need to be manually specified depending on the designers’ experience and insight, making the design result aleatory and even deviated from the real optimal solution. To tackle this problem, an experience-independent inverse design optimization method is proposed and applied to the redesign of a compressor cascade airfoil in this study. The experience-independent inverse design optimization method can automatically obtain the target pressure distribution along the cascade airfoil through the genetic algorithm, rather than through the manual specification approach. The shape of cascade airfoil is then solved by the adjoint method. The effectiveness of the experience-independent inverse design optimization method is demonstrated by two inverse design cases of the compressor cascade airfoil, i.e. the inverse design of only the suction surface and the inverse design of both the suction and pressure surfaces. The results show that the proposed inverse design method is capable of significantly improving the aerodynamic performance of the compressor cascade. At the examined flow condition, a thin airfoil profile is beneficial to flow accelerations near the leading edge and flow separation avoidance near the trailing edge. The proposed inverse design method is quite generic and can be extended to the three-dimensional inverse design of advanced compressor blades.

Comparative Study on Tip Clearance Flow Fields in Two Types of Transonic Centrifugal Compressor Impeller With Splitter Blades

2010 ◽  
Author(s):  
Kazutoyo Yamada ◽  
Yusuke Tamagawa ◽  
Hisataka Fukushima ◽  
Masato Furukawa ◽  
Seiichi Ibaraki ◽  
...  
Keyword(s):  
Leading Edge ◽  
Tip Clearance ◽  
Low Velocity ◽  
Blade Loading ◽  
Tip Clearance Flow ◽  
Tip Leakage ◽  
Transonic Centrifugal Compressor ◽  
Compressor Impeller ◽  
Clearance Flow ◽  
Velocity Region

Two types of transonic centrifugal compressor impeller with splitter blades, which are different in blade count, have been investigated in this study. RANS (Reynolds-Averaged Navier-Stokes) simulations were carried out for several operating conditions to clarify differences in aerodynamic performance characteristic and tip clearance flow field between the two compressors. The simulation shows that basically similar flow events happen in both compressors. A low velocity region is generated near the tip at low flow rate conditions, which results from an expansion of the tip leakage vortex. The low velocity region expands as the flow rate is decreased, and interacts with the pressure surface of the splitter blade near the leading edge. This causes a descent of the blade loading near the tip of the leading edge, and an accumulation of high entropy fluid near the casing-suction corner. Moreover, the tip clearance flow spills ahead of the leading edge of the splitter blade at near stall condition, and eventually the spillage happens at the full blade at stall condition. However, the major difference in solidity influences tip clearance flow/blade interaction, which leads to changes in the performance characteristics. In the impeller with low solidity, the tip leakage vortex breaks down with a large blockage effect because of high blade loading at the tip, which decreases the pressure ratio. The impeller with high solidity is subject to the spillage, which results in an early and large-scale stall that decreases the efficiency.

On Design of Transonic Fan Rotors by 3D Inverse Design Method

2006 ◽  
Author(s):  
Peixin Hu ◽  
Mehrdad Zangeneh ◽  
Benjamin Choo ◽  
Mohammad Rahmati
Keyword(s):  
Structural Integrity ◽  
Design Method ◽  
Leading Edge ◽  
Tip Clearance ◽  
Inverse Design ◽  
Pressure Loading ◽  
Tip Clearance Flow ◽  
Blade Thickness ◽  
Inverse Design Method ◽  
Transonic Fan

The application of 3D inverse design to transonic fans can offer designers many advantages in terms of reduction in design time and providing a more direct means of using the insight obtained into flow physics from CFD computations directly in the design process. A number of papers on application of inverse design method to transonic fans have already been reported. However, in order to apply this approach in product design a number of issues need to be addressed. For example, how can the method be used to affect and control the fan rotor characteristics? The robustness of the method and its ability to deal with accurate representation of leading and trailing edges, as well as tip clearance flow. In this paper the further enhancement of the 3D viscous transonic inverse design code TURBOdesign-2 and its application to the re-design of NASA37 and NASA67 rotors will be described. In this inverse design method the blade geometry can be computed by the specification of the blade loading (meridional derivative of rVθ) or the pressure loading. In both cases the blade normal thickness is specified to ensure structural integrity of the design. Improvements to the code include implementation of full approximation storage (FAS) multigrid technique in the solver, which increases the speed of the computation. This method allows the modification of blade thickness and pressure loading by B-splines. In addition improvements have been made in the treatment of proper leading edge geometry. Two well known examples of NASA 67 and NASA 37 rotors are used to provide a step-by-step guide to the application of the method to the design of transonic fan rotors. Improved designs are validated by commercial CFD code CFX.

A Robust Mixing Plane Method and its Application in 3D Inverse Design of Transonic Turbine Stages

2014 ◽  
Author(s):  
Saurya Ranjan Ray ◽  
Mehrdad Zangeneh
Keyword(s):  
Design Method ◽  
Flow Direction ◽  
Flow Analysis ◽  
Inverse Design ◽  
Plane Method ◽  
Design Variables ◽  
Wide Range ◽  
Inverse Design Method ◽  
Flow Variables ◽  
Flux Conservation

A robust mixing plane method satisfying interface flux conservation, non-reflectivity and retaining interface flow variation; valid at all Mach numbers and applicable for any machine configuration is formulated and implemented in a vertex based finite volume solver for flow analysis and inverse design of turbomachinery stage configurations. The formulation is based on superposing perturbed flow variables in the form of 3D characteristics obtained along the flow direction on the exchanged mixed out average quantities at the stage interface. A condition is derived in the mixed-out averaging procedure to distinguish between the subsonic and supersonic flow conditions at the interface. Using preconditioning technique, the new functionality is demonstrated to be applicable for a wide range of interface conditions and over different machine configurations with small spatial gap across the blade rows. The method is shown to satisfy flux conservation across the interface without generating spurious oscillations in the flow field at the domain boundaries and validated against available commercial solvers. Subsequently, a blade re-design approach in a multi-row configuration is conceptualised and demonstrated by the application of the 3D inverse design method on a single stage Low Pressure Turbine. Meridional load variation, stage reaction and blade stacking angle are considered as the design variables to explore the design space. Conducting design runs at a fixed mass flow boundary condition and similar overall loading condition; the optimised configuration is shown to satisfy redistributed meridional load, providing performance improvement while maintaining a similar level of flow rate and work extraction as the baseline configuration.

Secondary Flow, Separation and Losses in the NACA 48-Inch Centrifugal Impeller at Design and Off-Design Conditions

1988 ◽  
Author(s):  
John Moore ◽  
Joan G. Moore
Keyword(s):  
Secondary Flow ◽  
Leading Edge ◽  
Centrifugal Impeller ◽  
Tip Leakage ◽  
Laser Anemometry ◽  
Compressor Impeller ◽  
Overall Performance ◽  
Edge Separation ◽  
Insight Into ◽  
Flow Study

An elliptic flow calculation procedure has been used to model 3-D flow in the NACA 48–inch centrifugal impeller. The results demonstrate that fully elliptic steady flow calculations can be performed at design and off-design conditions. The calculations reproduce the measured overall performance and most of the features of the loss distributions observed in the NACA flow study. They give further insight into the complex 3-D flow with leading-edge separation and tip leakage. The calculated secondary flow patterns are presented and used to explain the convection of vortices in a more recent laser anemometry study of a centrifugal compressor impeller.

An Inverse-Design Method for Centrifugal Pump Impellers

2005 ◽  
Author(s):  
R. W. Westra ◽  
N. P. Kruyt ◽  
H. W. M. Hoeijmakers
Keyword(s):  
Design Method ◽  
Leading Edge ◽  
Inverse Design ◽  
Centrifugal Pumps ◽  
The Finite Element Method ◽  
Main Design ◽  
Blade Shape ◽  
The Mean ◽  
Inverse Design Method ◽  
Main Design Parameter

The development of an inverse-design method for the impellers of centrifugal pumps is presented. The flow inside the impeller channel is assumed to be irrotational, inviscid and incompressible. With the inverse-design method infinitely-thin impeller blades can be designed for a given meridional geometry and design conditions. The main design parameter is the mean-swirl distribution, which is specified from leading edge to trailing edge and from hub to shroud. The flow in the impeller channel is solved using the Finite Element Method, employing the mean-swirl distribution as a boundary condition. The blade shape is changed iteratively until the blade impenetrability condition is fulfilled. The method has been verified by considering a case for which an analytical solution is available and by reconstruction of an existing geometry, with known characteristics, using the inverse-design method. As an application of the method a mixed-flow impeller has been designed and the effect of changing the mean-swirl distribution on the resulting blade shape is clearly demonstrated.

Airfoil Shape Design via Elastic Surface Inverse Design Method

2014 ◽  
Author(s):  
M. Nili-Ahmadabadi ◽  
M. Safari ◽  
A. Ghaei ◽  
E. Shirani
Keyword(s):  
Convergence Rate ◽  
Pressure Distribution ◽  
Design Method ◽  
Flow Analysis ◽  
Flow Regimes ◽  
Inviscid Flow ◽  
Inverse Design ◽  
Elastic Surface ◽  
Design Algorithm ◽  
Inverse Design Method

In this research, a novel inverse design algorithm called, Elastic Surface Algorithm (ESA), is developed for viscose and inviscid external flow regimes. ESA is a physically based iterative inverse design method that uses flow analysis code to estimate the pressure distribution on the solid structure, i.e. airfoil, and a 2D solid beam finite element code to calculate the deflections due to the difference between the calculated and target pressure distribution. The proposed method is validated through the inverse design of three different airfoils. In addition, two design examples are presented to prove the robustness of the method in various flow regimes. Also, the convergence rate of this method is compared with flexible membrane method (MGM) and Ball-Spine Algorithm (BSA) methods in inviscid flow regime. The results of this study showed that not only the ESA method is an effective method for inverse design of airfoils, but also it can considerably increase the convergence rate in transonic flow regimes.

scholarly journals On 3D Inverse Design of Centrifugal Compressor Impellers With Splitter Blades

1998 ◽  
Author(s):  
M. Zangeneh
Keyword(s):  
Centrifugal Compressor ◽  
Design Methodology ◽  
Design Method ◽  
Leading Edge ◽  
Inverse Design ◽  
Conventional Design ◽  
Blade Shape ◽  
Edge Location ◽  
Stacking Condition ◽  
Inverse Design Method

In the design of centrifugal compressor impellers with splitter blades it is quite common to use the same blade shapes on the full and splitter blades with the splitters placed at the mid-pitch location. However, recent results using conventional design methodology have indicated that by moving the pitchwise location of the leading edge of the splitter it is possible to improve splitter performance. In this paper a 3D inverse design method is developed for the design of compressor impellers with splitters. In this design method the blades are designed subject to a specified distribution of the circulation on the full and splitter blades. The paper describes the choice of loading (or derivative of circulation with respect to meridional distance) and stacking condition to limit the complexity of the blade shape. Two different generic impellers are designed with different splitter leading edge location. The performance of these inverse designed impellers is then compared with the corresponding conventional impellers by using a 3D viscous code at design and off-design conditions.

Effects of Blade Loading on Pump Inducer Performance and Flow Fields

2002 ◽  
Author(s):  
Kosuke Ashihara ◽  
Akira Goto
Keyword(s):  
Design Method ◽  
Three Dimensional ◽  
Leading Edge ◽  
Flow Fields ◽  
Inverse Design ◽  
Water Model ◽  
Experimental Investigations ◽  
Blade Loading ◽  
Edge Loading ◽  
Inverse Design Method

Numerical and experimental investigations were performed to study the effects of blade loading on pump inducer performance and flow fields. To compare the performance of inducers with different blade loadings, a three-dimensional inverse design method was applied to control the blade loading distribution of inducers. Firstly, a conventional helical inducer was designed. The blade number is three and the blade angle at the tip was chosen by the conventional design method. Then, two inducers were designed using a three-dimensional inverse design method with different blade loading distributions. One inducer was designed with fore-loading and the other was designed with aft-loading, but both inducers were designed with no leading edge loading. These two inducers have the same design specification as the conventional helical inducer. The CFD (Computational Fluid Dynamics) analyses and water model tests were performed on these three inducers. Both results showed that the inlet backflow characteristics of the 3-D inverse design inducers are improved from those of the conventional inducer. It was also found that the inlet backflow characteristics of inducers that have no leading edge loading are almost same despite different blade loading distributions. The inducer designed with fore-loading showed almost the same suction performance as the conventional inducer. Cavitation visualization and FFT analysis of unstable phenomena were also performed in this study.

Sign in / Sign up

Export Citation Format

Share Document