Inverse Design of Centrifugal Compressor Vaned Diffusers in Inlet Shear Flows

1996 ◽  
Vol 118 (2) ◽  
pp. 385-393 ◽  
Author(s):  
M. Zangeneh
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Design Method ◽  
Three Dimensional ◽  
Internal Flow ◽  
Inviscid Flow ◽  
Inverse Design ◽  
Flow Conditions ◽  
Inlet Flow ◽  
Blade Thickness

A three-dimensional inverse design method in which the blade (or vane) geometry is designed for specified distributions of circulation and blade thickness is applied to the design of centrifugal compressor vaned diffusers. Two generic diffusers are designed, one with uniform inlet flow (equivalent to a conventional design) and the other with a sheared inlet flow. The inlet shear flow effects are modeled in the design method by using the so-called “Secondary Flow Approximation” in which the Bernoulli surfaces are convected by the tangentially mean inviscid flow field. The difference between the vane geometry of the uniform inlet flow and nonuniform inlet flow diffusers is found to be most significant from 50 percent chord to the trailing edge region. The flows through both diffusers are computed by using Denton’s three-dimensional inviscid Euler solver and Dawes’ three-dimensional Navier–Stokes solver under sheared in-flow conditions. The predictions indicate improved pressure recovery and internal flow field for the diffuser designed for shear inlet flow conditions.

scholarly journals Inverse Design of Centrifugal Compressor Vaned Diffusers in Inlet Shear Flows

1994 ◽  
Author(s):  
M. Zangeneh
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Design Method ◽  
Internal Flow ◽  
Inviscid Flow ◽  
Inverse Design ◽  
Navier Stokes ◽  
Inlet Flow ◽  
Blade Thickness ◽  
The Difference

A 3D inverse design method in which the blade (or vane) geometry is designed for specified distributions of circulation and blade thickness is applied to the design of centrifugal compressor vaned diffusers. Two generic diffusers are designed, one with uniform inlet flow (equivalent to a conventional design) and the other with a sheared inlet flow. The inlet shear flow effects are modelled in the design method by using the so-called “Secondary Flow Approximation” in which the Bernoulli surfaces are convected by the tangentially mean inviscid flow field. The difference between the vane geometry of the uniform inlet flow and non-uniform inlet flow diffusers is found to be most significant from 50% chord to the trailing edge region. The flow through both diffusers are computed by using Denton’s 3D inviscid Euler solver and Dawes’ 3D Navier-Stokes solver under sheared inflow conditions. The predictions indicate improved pressure recovery and internal flow field for the diffuser designed for shear inlet flow conditions.

Optimization of 6.2:1 Pressure Ratio Centrifugal Compressor Impeller by 3D Inverse Design

2011 ◽  
Author(s):  
M. Zangeneh ◽  
N. Amarel ◽  
K. Daneshkhah ◽  
H. Krain
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Mechanical Performance ◽  
Design Method ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Inverse Design ◽  
Transonic Compressor ◽  
Design Variables ◽  
Compressor Impeller

In this work, the redesign of a centrifugal transonic compressor impeller with splitter blades by means of the three-dimensional inverse design code TURBOdesign-1 is presented. The basic design methodology for impellers with splitter blades is outlined and is applied in a systematic way to improve the aero/mechanical performance of a transonic 6.2:1 pressure ratio centrifugal compressor impeller. The primary design variables are the main and splitter blades loading and their thickness distributions, the splitter to main blade work ratio, as well as the span-wise swirl distribution. The flow in the original and redesigned impellers are then analyzed by means of a commercial CFD code (ANSYS CFX). The predicted flow field for the original impeller is compared with detailed L2F measurements inside and outside the impeller. The validated CFD results are used to compare the flow field in the optimized and original impeller. It is shown that the inverse design method could be effectively used to control the position and strength of the shock waves, eliminate flow separation and hence obtain a more uniform impeller exit flow in order to improve the aerodynamic performance. In addition, some results are presented on the comparison of stress and vibration in both impellers.

Inverse Design of 3D Compressor Blades With Adjoint Method

2003 ◽  
Author(s):  
June Chung ◽  
Jeonghwan Shim ◽  
Ki D. Lee
Keyword(s):  
High Speed ◽  
Adjoint Method ◽  
Design Method ◽  
Computational Cost ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Internal Flow ◽  
Adjoint System ◽  
Inverse Design ◽  
Compressor Blades

A three-dimensional (3D) CFD-based design method for high-speed axial compressor blades is being developed based on the discrete adjoint method. An adjoint code is built corresponding to RVC3D, a 3D turbomachinery Navier-Stokes analysis code developed at NASA Glenn. A validation study with the Euler equations indicates that the adjoint sensitivities are sensitive to the choice of boundary conditions for the adjoint variables in internal flow problems and constraints may be needed on internal boundaries to capture proper physics of the adjoint system. The design method is demonstrated with inverse design based on Euler physics, and the results indicate that the adjoint design method produces efficient 3D designs by drastically reducing the computational cost.

scholarly journals An improved inverse method for multirow blades of turbomachinery

2020 ◽  
Vol 234 (22) ◽  
pp. 4433-4443
Author(s):  
Li Aiting ◽  
Zhu Yangli ◽  
Li Wen ◽  
Wang Xing ◽  
Qin Wei ◽  
...  
Keyword(s):  
Flow Structure ◽  
Inverse Method ◽  
Design Method ◽  
Spline Interpolation ◽  
Thickness Distribution ◽  
Three Dimensional ◽  
Internal Flow ◽  
Navier Stokes ◽  
Virtual Displacement ◽  
Blade Thickness

A three-dimensional viscous inverse design method is improved and extended to multirow blades environment. The inverse method takes load distribution as optimization objective and is implemented into the time-marching finite-volume Reynolds-averaged Navier–Stokes solver. The camber line of rotor blade is updated by virtual displacement, which is calculated by characteristic compatibility relations according to the difference between target and actual load so as to control the location and intensity of shock wave, and realize the optimization of flow structure and reduction flow separation. The inlet and outlet geometry angles of stator blade are adjusted in real time according to the inlet and outlet flow angles. Thus, it is computationally ensured that the blade row interactions are accounted and optimization process is carried out under the design condition. To preserve the robustness of calculation, the maximum virtual displacement is limited by Y+ <10 and the camber line is smoothed via cubic B-spline interpolation. The complete blade profile is then generated by adding the prescribed blade thickness distribution to the camber line. The effectiveness of the method is demonstrated in the optimization of Stage35 compressor stage. Numerical results showed that this inverse method can effectively improve the internal flow structure and optimize the matching between blade rows, and this method is robust, efficient, and flexible.

On the Design Criteria for Suppression of Secondary Flows in Centrifugal and Mixed Flow Impellers

1998 ◽  
Vol 120 (4) ◽  
pp. 723-735 ◽  
Author(s):  
M. Zangeneh ◽  
A. Goto ◽  
H. Harada
Keyword(s):  
Flow Field ◽  
Pressure Distribution ◽  
Centrifugal Compressor ◽  
Design Method ◽  
Three Dimensional ◽  
Design Guidelines ◽  
Secondary Flows ◽  
Mixed Flow ◽  
Optimum Pressure ◽  
Specific Speed

In this paper, for the first time, a set of guidelines is presented for the systematic design of mixed flow and centrifugal compressors and pumps with suppressed secondary flows and a uniform exit flow field. The paper describes the shape of the optimum pressure distribution for the suppression of secondary flows in the impeller with reference to classical secondary flow theory. The feasibility of achieving this pressure distribution is then demonstrated by deriving guidelines for the design specifications of a three-dimensional inverse design method, in which the blades are designed subject to a specified circulation distribution or 2πrVθ. The guidelines will define the optimum choice of the blade loading or ∂rVθ/∂m and the stacking condition for the blades. These guidelines are then used in the design of three different low specific speed centrifugal pump impellers and a high specific speed industrial centrifugal compressor impellers. The flows through all the designed impellers are computed numerically by a three-dimensional viscous code and the resulting flow field is compared to that obtained in the corresponding conventional impeller. The results show consistent suppression of secondary flows in all cases. The design guidelines are validated experimentally by comparing the performance of the inverse designed centrifugal compressor impeller with the corresponding conventional impeller. The overall performance of the stage with the inverse designed impeller with suppressed secondary flows was found to be 5 percent higher than the conventional impeller at the peak efficiency point. Exit flow traverse results at the impeller exit indicate a more uniform exit flow than that measured at the exit from the conventional impeller.

Optimization of Microturbine Aerodynamics Using CFD, Inverse Design and FEM Structural Analysis: 2nd Report — Turbine Design

2004 ◽  
Author(s):  
Hiroyoshi Watanabe ◽  
Hidenobu Okamoto ◽  
Shijie Guo ◽  
Akira Goto ◽  
Mehrdad Zangeneh
Keyword(s):  
Structural Reliability ◽  
Design Method ◽  
Thickness Distribution ◽  
Three Dimensional ◽  
Inverse Design ◽  
Blade Profile ◽  
Performance Improvements ◽  
Radial Turbine ◽  
Blade Thickness ◽  
Inverse Design Method

In this second report, a new aerodynamic design is presented for a radial turbine stage of a microturbine engine. To optimize three-dimensional (3-D) flows, an inverse design method, in which 3-D blade geometry is numerically obtained for specified blade loading distribution, has been applied together with numerical assessment using CFD (Computational Fluid Dynamics) and FEM (Finite Element Method). The runner blade profile along the hub surface was modified to attain nearly radially arranged blade elements especially at the exducer part of the radial turbine in order to achieve required structural strength. Also the blade thickness distribution was optimized to avoid vibration resonance and to meet creep strength requirements. The blade profile along the shroud surface was optimized via 3-D inverse design and CFD. CFD predicted aerodynamic performance of the modified turbine runner was confirmed to be similar to that of the fully 3-D blade shape, while maintaining structural reliability. The turbine nozzle also has been re-designed by using the inverse design method, with stage performance improvements confirmed by stage calculations using CFD.

scholarly journals The Unsteady Numerical Simulation and Fluid-Structure Interaction Analysis of TLB600-700 Desulphurization Pump

2014 ◽  
Vol 6 ◽  
pp. 191697
Author(s):  
Xiaoke He ◽  
Jianrui Liu ◽  
Dengpeng Fu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Internal Flow ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Design Requirements ◽  
Unsteady Numerical Simulation

Based on the design theory of liquid-solid two-phase flow centrifugal pump, a new type TLB600-700 desulphurization pump was designed with huge distortions blades design method and impeller inlet super long extension blades design method. Three-dimensional model of internal flow field in TLB600-700 desulphurization pump was built by software PROE5.0, and the three-dimensional unsteady numerical simulation of the internal flow field was calculated, which revealed that the rotor-stator interaction between rotating impeller and volute is the reason why unstable flow generated. Statics analysis was carried out on the impeller in the stationary flow state with the method of fluid-structure interaction, and results indicated that the impeller strength and stiffness meet the design requirements. External characteristic test results of TLB600-700 desulphurization pump showed that all parameters of desulphurization pump designed by innovative method meet design requirements; especially the pump efficiency was increased by 4.15% higher than Chinese national standard.

On the role of three-dimensional inverse design methods in turbomachinery shape optimization

1999 ◽  
Vol 213 (1) ◽  
pp. 27-42 ◽  
Author(s):  
M Zangeneh ◽  
A Goto ◽  
H Harada
Keyword(s):  
Flow Field ◽  
Inverse Method ◽  
Design Method ◽  
Three Dimensional ◽  
Design Guidelines ◽  
Secondary Flows ◽  
Inverse Design ◽  
Vaned Diffuser ◽  
Oil Flow ◽  
Inverse Design Method

The application of a three-dimensional (3D) inverse design method in which the blade geometry is computed for a specified distribution of circulation to the design of turbomachinery blades is explored by using two examples. In the first instance the method is applied to the design of radial and mixed flow impellers to suppress secondary flows. Based on our understanding of the fluid dynamics of the flow in the impeller, simple guidelines are developed for input specification of the inverse method in order to systematically design impellers with suppressed secondary flows and a more uniform exit flow field. In the second example the method is applied to the design of a vaned diffuser. Again based on the understanding of the detailed flow field in the diffuser obtained by using 3D viscous calculations and oil flow visualizations, simple design guidelines are developed for input specification to the inverse method in order to suppress corner separation. In both cases the guidelines are verified numerically and in the case of the diffuser further experimental validation is presented.

Impeller Flow Field Measurement and Analysis

1991 ◽  
Vol 113 (4) ◽  
pp. 670-679 ◽  
Author(s):  
J. R. Fagan ◽  
S. Fleeter
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Internal Flow ◽  
Mean Flow ◽  
Suction Surface ◽  
Flow Models ◽  
Flow Phenomena ◽  
Series Of Experiments ◽  
Moderate Scale

A series of experiments are performed to investigate and quantify the three-dimensional mean flow field in centrifugal compressor flow passages and to evaluate contemporary internal flow models. The experiments include the acquisition and analysis of LDV data in the impeller passages of a low-speed moderate-scale research mixed-flow centrifugal compressor operating at its design point. Predictions from a viscous internal flow model are then correlated with these data. The LDV data show the traditional jet-wake structure observed in many centrifugal compressors, with the wake observed along the shroud 70 percent of the length from the pressure to suction surface. The viscous model predicts the major flow phenomena. However, the correlations of the viscous predictions with the LDV data were poor.

scholarly journals Numerical Investigation of Internal Flow Field for Modified Design of Eckardt Backswept Impeller

1998 ◽  
Author(s):  
JongSik Oh
Keyword(s):  
Flow Field ◽  
Static Pressure ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Internal Flow ◽  
Aerodynamic Characteristics ◽  
Uniform Flow ◽  
Spanwise Direction ◽  
Vaneless Diffuser ◽  
Blade Thickness

The three dimensional blade shape of Eckardt’s backswept impeller was modified, expecting better aerodynamic performance of the internal flow field. Blade angle distributions and parts of the meridional contours were changed, while impeller diameter, blade number, blade thickness and blade inlet and exit angles remained unchanged. The casing contour in the vaneless diffuser is additionally changed in a smooth manner to obtain 15% pinched flow channel at the exit. With the help of the three dimensional compressible Navier-Stokes analysis method, some improvements in the aerodynamic characteristics of the internal flow field were found; a more uniform flow field in the circumferential direction at impeller discharge was established, and a more favorable rise of static pressure near the casing in the impeller passage was made. A more effective increase of static pressure in the vaneless diffuser was also found. But a less uniform flow field in the spanwise direction at impeller exit resulted. The same levels of total-to-total pressure ratio and isentropic efficiency of the compressor were obtained, while an increase of choking flow rate was obtained due to increased throat area.

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