Multidisciplinary 3D-Optimization of a Fan Stage Performance Map With Consideration of the Static and Dynamic Rotor Mechanics

2010 ◽  
Author(s):  
Ulrich Siller ◽  
Marcel Aulich
Keyword(s):  
Pressure Ratio ◽  
Stability Margin ◽  
Structural Mechanics ◽  
Aerodynamic Performance ◽  
Response Surfaces ◽  
Optimization Process ◽  
Design Parameters ◽  
Optimization Strategy ◽  
Rotor Aerodynamics ◽  
High Pressure Ratio

Achievement of an optimal compressor design with respect to its aerodynamic performance and feasible structural mechanics within an automated optimization process is subject of this paper. The compressor considered is a highly loaded, transonic fan stage, designed for achievement of a very high pressure ratio. To ensure operation in highly integrated installation conditions, a sufficient stability margin is of major concern. Multiple aerodynamic operating points at two rotational speeds allowed optimization of both the stability margin and the working line stage efficiency. On the part of structural mechanics, several static stress criteria were addressed for definite blade regions as well as the dynamic blade behavior in terms of the Campbell diagram. An optimization strategy was chosen, which targeted firstly on the fulfillment of multiple mechanical and aerodynamical constraints, while the aerodynamic performance was under constraint itself. Upon achievement, optimization aimed for maximum aerodynamic performance while keeping mechanics feasible. Response surfaces have been incorporated in the optimization process to reconcile costly high fidelity CFD and structural simulations with the large number of 114 free design parameters. Furthermore, optimization on these models enabled a successfully accomplishment of the constraint issue by a large number of numerically cheaper fitness evaluations. Starting from an already optimized baseline configuration, the current work targeted an improvement of the rotor aerodynamics in the transonic hub region and the resolution of previously unsolved problems concerning the rotor structural mechanics. Free design parameters were hub and casing contours in the rotor part, the shape of the leading and trailing blade edges and a high degree of freedom for rotor profile sections in the lower half of the blade.

Aeroelastic Properties of Closely Spaced Modes for a Highly Loaded Transonic Fan

2008 ◽  
Author(s):  
Hans Ma˚rtensson ◽  
Ste´fan Sturla Gunnsteinsson ◽  
Damian M. Vogt
Keyword(s):  
Rotational Speed ◽  
Pressure Ratio ◽  
Stability Margin ◽  
Frequency Separation ◽  
Mode Shapes ◽  
Compressor Blades ◽  
Aeroelastic System ◽  
High Pressure Ratio ◽  
Mode Separation ◽  
Centrifugal Stiffening

In the design of modern compressor blades of wide chord (low aspect ratio) type it is often hard to avoid having modes that are close to each other in frequency. Modes which are closely spaced can interact dynamically. Mistuning and localization of stresses are known problems with this. A potential problem with this is also the possibility of coalescence flutter of the modes. Even if the modes are frequency separated at zero rotational speed, the centrifugal stiffening may cause the modes to attract and even cross (or veer) at some rotational speed. In design, mode separation criteria are sometimes applied in order to minimize the risk of encountering unknown dynamic phenomena. This study is performed to better understand the dynamics of closely spaced modes with respect to risk for coalescence flutter. A reduced order aeroelastic system is then constructed that describes the interaction between the different modes. The aeroelastic couplings are then calculated for the 2 mode system. The method is general in terms of mode shapes and number of interacting modes. A parametrical study is performed in order to study how strongly the modes interact when the frequency separation is decreased and if there is a risk of destructive coalescence flutter. The investigation is performed on a high pressure ratio front stage fan blade. The tendency of the modes to interact depends on the strength of the coupling compared to the strength of the pure structural modes. The tendency towards instability was increased in cases where the stability margin was smaller of the single modes. The results can be considered to support a separation criterion of 2% for the lower. A re-evaluation should be considered if lighter blade material and increased loads are to be used.

Aerodynamic Analysis and Multi-Objective Optimization Design of a High Pressure Ratio Centrifugal Impeller

2014 ◽  
Author(s):  
Zhendong Guo ◽  
Zhiming Zhou ◽  
Liming Song ◽  
Jun Li ◽  
Zhenping Feng
Keyword(s):  
Data Mining ◽  
High Pressure ◽  
Pressure Ratio ◽  
Differential Evolution Algorithm ◽  
Aerodynamic Performance ◽  
Centrifugal Impeller ◽  
Tip Leakage Flow ◽  
Pareto Solutions ◽  
Multi Objective ◽  
High Pressure Ratio

The design of high pressure ratio impellers is a challenging task. SRV2-O, a typical high pressure ratio centrifugal impeller is selected for the research. A good understanding of flow characteristics in the passage of SRV2-O is obtained by using 3D Reynolds-Averaged Navier-Stokes (RANS) solutions upon numerical validation. It confirms that tip leakage flow and shock wave boundary layer interactions produce the primary energy loss in this transonic impeller. A 3D multi-objective aerodynamic optimization and data mining method named BMOE is presented and programmed by integrating a self-adaptive multi-objective differential evolution algorithm SMODE, 3D blade parameterization method based on non-uniformed B-Spline, RANS solver technique and self-organization map (SOM) based data mining technique. Using BMOE, multi-objective aerodynamic design optimization and data mining is performed for SRV2-O. 14 Pareto solutions are obtained for maximizing isentropic efficiency and total pressure ratio of the impeller. Three typical Pareto solutions, Design A with the highest efficiency, Design B with the higher efficiency and larger pressure ratio and Design C with the maximum pressure ratio, are analyzed. Detailed analysis indicates that the aerodynamic performance of optimized designs is greatly improved. Furthermore, by SOM-based data mining on optimization results, trade-off relation between objective functions and parameter influence mechanism on impeller aerodynamic performance are visualized and explored.

Analyses and Optimization of a Propulsion Cycle for Unmixed High Bypass Turbofan

2008 ◽  
Author(s):  
Adel Ghenaiet
Keyword(s):  
Fuel Consumption ◽  
Pressure Ratio ◽  
Specific Fuel Consumption ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
High Pressure Ratio ◽  
Turbine Inlet ◽  
Design Variables ◽  
Bypass Ratio

This paper deals with a parametric study and an optimization for the design variables of a high bypass unmixed turbofan equipping commercial aircrafts. The objective of the first part of this study is to highlight the effects of the principal design parameters (bypass ratio, compression ratios, turbine inlet temperature etc..) on the uninstalled performance, in terms of specific thrust and specific fuel consumption. The second part concerns the optimization, aiming at finding the optimum design parameters concurrently minimizing the specific fuel consumption at cruise, and meeting the thrust requirement at takeoff. The cycle analyzer (on-design and off-design) as coupled to the optimization algorithm MMFD by adopting a random multi-starts search strategy is shown to be stable and converging. The predefined requirements and constraints have dictated utilizing an engine with a high-bypass ratio, high-pressure ratio and a moderate turbine inlet temperature. In general, the obtained results compare fairly well with typical data available for an equivalent ‘reference’ engine. This elaborated methodology is shown to be consistent with the conceptual design requirements and accuracy, because, it does not use components’ characteristics, and operates on simplifying assumptions. This present methodology can be readily adapted for other configurations of aero-engines as well, and easily integrated in a multi-disciplinary design approach.

Numerical Investigation of Low Solidity Vaned Diffuser Performance in a High-Pressure Centrifugal Compressor: Part I — Influence of Vane Solidity

2007 ◽  
Author(s):  
JongSik Oh ◽  
Giri L. Agrawal
Keyword(s):  
High Pressure ◽  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Limited Range ◽  
Design Flow ◽  
Design Parameters ◽  
Moderate Pressure ◽  
Vaned Diffuser ◽  
High Pressure Ratio ◽  
Wide Operating

The LSD (Low Solidity Diffuser) is becoming popular in most industrial centrifugal compressor designs because it is found to offer a wide operating flow range while maintaining a similar level of efficiency as in case of conventional vaned diffusers. Most related studies have been for low or moderate pressure ratio machines providing a limited range of design information for high-pressure ratio compressors. As a first step forward information of design parameters, a numerical CFD investigation was applied to a high-pressure industrial centrifugal compressor of design total-to-static pressure ratio of 4.0 with LSDs of NACA65-series profiles whose solidity varies from 0.452 to 0.968 in 5 cases with all the other design parameters fixed. Near design flow, the case of 0.839 solidity has the highest isentropic total-to-static efficiency. Other performance changes are accordingly investigated.

Optimal Design of Impeller for Centrifugal Compressor Under the Influence of Fluid-Structure Interaction

2015 ◽  
Author(s):  
Hyun-Su Kang ◽  
Yoo-June Song ◽  
Youn-Jea Kim
Keyword(s):  
Optimal Design ◽  
Centrifugal Compressor ◽  
Fluid Structure Interaction ◽  
Aerodynamic Performance ◽  
Response Surfaces ◽  
Design Parameters ◽  
Flow Induced Vibration ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Whole Process

In this study, a method for optimal design of impeller for centrifugal compressor under the influence of flow-induced vibration (FIV) using fluid-structure interaction (FSI) and response surface method (RSM) was studied. Numerical simulation was conducted using ANSYS with various configurations of impeller geometry. Each of the design parameters was divided into 3 levels. Total 15 design points were planned by central composite design (CCD) method, which is one of the design of experiment (DOE) techniques. Response surfaces generated based on the DOE results were used to find the optimal shape of impeller for high aerodynamic performance. The whole process of optimization was conducted using ANSYS Design Xplorer (DX). Through the optimization, structural stability and aerodynamic performance of centrifugal compressor were improved.

scholarly journals Investigation on the Optimal Design and Flow Mechanism of High Pressure Ratio Impeller with Machine Learning Method

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Weilin Yi ◽  
Hongliang Cheng
Keyword(s):  
Machine Learning ◽  
High Pressure ◽  
Flow Field ◽  
Performance Improvement ◽  
Pressure Ratio ◽  
Leading Edge ◽  
Design Parameters ◽  
Support Vector ◽  
Peak Efficiency ◽  
High Pressure Ratio

The optimization of high-pressure ratio impeller with splitter blades is difficult because of large-scale design parameters, high time cost, and complex flow field. So few relative works are published. In this paper, an engineering-applied centrifugal impeller with ultrahigh pressure ratio 9 was selected as datum geometry. One kind of advanced optimization strategy including the parameterization of impeller with 41 parameters, high-quality CFD simulation, deep machine learning model based on SVR (Support Vector Machine), random forest, and multipoint genetic algorithm (MPGA) were set up based on the combination of commercial software and in-house python code. The optimization objective is to maximize the peak efficiency with the constraints of pressure-ratio at near stall point and choked mass flow. Results show that the peak efficiency increases by 1.24% and the overall performance is improved simultaneously. By comparing the details of the flow field, it is found that the weakening of the strength of shock wave, reduction of tip leakage flow rate near the leading edge, separation region near the root of leading edge, and more homogenous outlet flow distributions are the main reasons for performance improvement. It verified the reliability of the SVR-MPGA model for multiparameter optimization of high aerodynamic loading impeller and revealed the probable performance improvement pattern.

Aerodynamic Investigation of a High Pressure Ratio Turbo-Expander for Organic Rankine Cycle Applications

2012 ◽  
Author(s):  
Michele Marconcini ◽  
Filippo Rubechini ◽  
Andrea Arnone ◽  
Alberto Scotti Del Greco ◽  
Roberto Biagi
Keyword(s):  
High Pressure ◽  
Pressure Ratio ◽  
Aerodynamic Performance ◽  
Performance Estimation ◽  
Primary Concern ◽  
Viscous Effects ◽  
Cfd Modelling ◽  
Mechanical Integrity ◽  
High Pressure Ratio ◽  
The Impact

The design of radial-inflow turbines usually relies on one-dimensional or mean-line methods. While these approaches have so far proven to be quite effective, they can not assist the designer in coping with some important issues, such as mechanical integrity and complex flow features. Turbo-expanders are in general characterized by fully three-dimensional flow fields, strongly influenced by viscous effects and passage curvature. In particular, for high pressure ratio applications, such as in organic Rankine cycles, supersonic flow conditions are likely to be reached, thus involving the formation of a shock pattern which governs the interaction between nozzle and wheel components. The nozzle shock waves are periodically chopped by the impeller leading edge, and the resulting unsteady interaction is of primary concern for both mechanical integrity and aerodynamic performance. This work is focused on the aerodynamic issues and addresses some key aspects of the CFD modelling in the numerical analysis of turbo-expanders. Calculations were carried out by adopting models with increasing level of complexity, from the classical steady-state approach to the full-stage, time-accurate one. Results are compared in details and the impact of the computational model on the aerodynamic performance estimation is discussed.

Effects of Probe Stem Surface Suction on the Aerodynamic Performance of a Compressor

2021 ◽  
Author(s):  
Yafei Zhong ◽  
Hongwei Ma ◽  
Yi Yang
Keyword(s):  
Flow Field ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Stability Margin ◽  
Aerodynamic Performance ◽  
Vortex Identification ◽  
Flow Angle ◽  
Surface Suction ◽  
Three Dimensional Models ◽  
Downstream Flow

Abstract Pneumatic probes can be used to obtain the flow field parameters such as pressure, temperature and air flow angle, and has been widely used to measure the flow field in compressors. When probes are inserted into the compressor to measure the flow field, the probe stems will cause blockage in the flow field and interfere with it, reducing the pressure ratio and efficiency of the compressor. This paper proposes a method to reduce the interference of the stems by their surface suction. Three-dimensional models of a compressor with different types of probe stems were established. Computational Fluid Dynamics (CFD) simulations of the flow within a low-speed compressor without/with the probe stems and the stems having surface suction holes were conducted. The involved numerical methods were validated by the experimental data. The effects of the surface suction holes on the performance of this compressor were compared and analyzed in terms of blockage coefficient in the passage by the vortex identification method. The results show that probe stem surface suction can reduce the blockage of the stems on the downstream flow field. Compared with the situation of no suction, there is an optimal suction mass flow rate that can minimize the adverse effect of probe stems on the compressor aerodynamic performance. For the same type of the probe stems, the compressor performances, i.e., pressure ratio, efficiency and stability margin, are recovered with the increase of the number of suction holes along the span-wise direction.

Design and Application of a Single Gas Turbine Matched with Two Tandem Driven Centrifugal Compressors

1980 ◽  
Vol 102 (1) ◽  
pp. 120-123
Author(s):  
D. W. Wood ◽  
R. G. Reid
Keyword(s):  
Gas Turbine ◽  
Pressure Ratio ◽  
High Volume ◽  
Aerodynamic Performance ◽  
Volume Transmission ◽  
Centrifugal Compressors ◽  
High Pressure Ratio ◽  
Wide Range ◽  
Gas Turbine Compressor ◽  
Design And Application

This paper deals with the design and application of a 29,000 bhp (21,625 KW) gas turbine-compressor unit to perform the duties of high pressure ratio/low volume (storage) and low pressure ratio/high volume (transmission). To achieve this wide range of requirements, a single gas turbine was matched with two tandem driven centrifugal compressors. The paper describes the considerations and the techniques used to select the gas turbine, compressor aerodynamic performance and match the gas turbine and compressors.

scholarly journals Total Cost Minimization of a High-Pressure Natural Gas Network

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
F. Tabkhi ◽  
L. Pibouleau ◽  
C. Azzaro-Pantel ◽  
S. Domenech
Keyword(s):  
High Pressure ◽  
Cost Minimization ◽  
Flow Direction ◽  
Pressure Ratio ◽  
Mixed Integer ◽  
Design Parameters ◽  
Optimization Strategy ◽  
Customer Requirements ◽  
Gas Network ◽  
And Storage

This paper deals with a high-pressure gas pipeline optimization, where the problem is to find the design properties of the pipelines and necessary compressor stations to satisfy customer requirements, using available supply gas and storage capacities. The considered objective function is the total annualized cost, including the investment and operating costs. The binary variables used to represent the flow direction of pipelines lead to a mixed integer nonlinear programming problem, solved by using the standard branch and bound solver in GAMS. The optimization strategy provides the main design parameters of the pipelines (diameters, pressures, and flow rates) and the characteristics of compressor stations (location, suction pressure, pressure ratio, station throughput, fuel consumption, and station power consumption) to satisfy customer requirements.

Sign in / Sign up

Export Citation Format

Share Document