A Multi-Fidelity Sampling Method for Efficient Design and Optimization of Centrifugal Compressor Impellers

2018 ◽  
Author(s):  
Christoph Schemmann ◽  
Marius Geller ◽  
Norbert Kluck
Keyword(s):  
Centrifugal Compressor ◽  
Sampling Method ◽  
Latin Hypercube Sampling ◽  
Design Parameters ◽  
Efficient Design ◽  
Design And Optimization ◽  
Computational Expense ◽  
Compressor Impeller ◽  
Good Coverage ◽  
Complete Operation

The optimization of a centrifugal compressor impeller is a challenge for established strategies and algorithms, as the interactions between the geometric design parameters and the aerodynamic and structural performance of the system are highly complex. Furthermore many geometrically valid designs are unusable in terms of structure mechanics or flow physics. Due to the complex parameter correlations, a simple limitation of the parametric space is no option, as possibly beneficial parameter combinations could be ruled out. To obtain a meaningful optimization result, the complete operation range of the compressor has to be taken into account which adds further complexities in terms of the optimization process and the computational expense. The combination of these issues leads to a complicated optimization scenario. The aim of the presented work is the reduction of the computational expense required to generate a high quality metamodel for optimization. This goal shall be achieved by the development of a multi-fidelity sampling method. The basic idea is to use preliminary of low-fidelity information from empirical data or fast analytical methods to identify promising regions of the parameter space. Then the samples of the DOE are concentrated in these areas while still maintaining a good coverage of the whole applicable design space. This ensures that no beneficial designs are ruled out which were not recommended by preliminary information. The points of the resulting DOE are computed by CFD and FEA computations and used to generate the metamodel which is used for the optimization. The method is tested by generating a metamodel used for compressor optimization. The results are compared to an optimization using a metamodel based on a conventional Latin hypercube sampling.

Detuning the Natural Frequencies of a Compressor Impeller Blade Through the Design Optimization

2015 ◽  
Author(s):  
Alexander O. Pugachev ◽  
Alexander V. Sheremetyev ◽  
Viktor V. Tykhomirov ◽  
Alexey V. Petrov
Keyword(s):  
Natural Frequency ◽  
Centrifugal Compressor ◽  
Natural Frequencies ◽  
Optimization Problems ◽  
Detailed Comparison ◽  
Element Model ◽  
Optimization Method ◽  
Design Parameters ◽  
Impeller Blade ◽  
Compressor Impeller

This paper describes a theoretical approach to shift individual natural frequencies of centrifugal compressor impeller blades. The approach applies sizing optimization of blade’s geometry using a gradient-based optimization method. Calculation of gradients is carried out by the finite-difference method. A new centrifugal compressor blade profile generator incorporating a blade parametrization procedure is developed. The blade’s geometry is parametrized using intuitive geometric parameters. Five design parameters related to the length of the sectional profile generator line, profile thicknesses and rotation angles at hub and shroud are defined for each of the blade sectional profiles. In addition, two global design parameters are defined to control rigid rotation of the blade hub and shroud sections in circumferential direction. Four nonlinear optimization problems containing multiple frequency constraints and constraints on the static equivalent stresses are considered. The optimization aims are either shifting a particular natural frequency of a blade or minimization of blade’s mass. For instance, one of the considered optimization problems is to decrease the 1st natural frequency of an impeller blade by 5%, while the 2nd and the 3rd natural frequencies must be simultaneously increased by 5%. The analysis is applied to the centrifugal compressor of a small-size turboprop engine. A three-dimensional finite element model of the impeller blade is developed in ANSYS Mechanical software package to perform static and modal analyses. The results of the optimization show that the code can meet defined objectives and constraints with reasonable accuracy. A detailed comparison of optimized profiles with the baseline geometry is provided.

3D Multi-Disciplinary Inverse Design Based Optimization of a Centrifugal Compressor Impeller

2014 ◽  
Author(s):  
Mehrdad Zangeneh ◽  
Fred Mendonça ◽  
Youngwon Hahn ◽  
Jack Cofer
Keyword(s):  
Response Surface ◽  
Centrifugal Compressor ◽  
Inverse Design ◽  
Design Parameters ◽  
Operating Range ◽  
Multi Objective ◽  
Development Times ◽  
Stable Operating ◽  
Compressor Impeller ◽  
3D Fea

Design of centrifugal compressors in different applications from industrial to turbochargers to aeroengine is subject to difficult multi-disciplinary ( aerodynamics and mechanical) and multipoint/multi-objective requirements. These multi-disciplinary and multi-point requirements have to be met by iterations between aerodynamics and mechanical design, leading to long development times and bottlenecks in the design process. In this paper, for the first time, a commercially available solution, compatible with industrial development times, is presented for 3D multi-disciplinary and multi-point design optimisation of turbomachinery blades. The methodology combines 3D inverse design method, automatic optimizers, 3D CFD and 3D FEA codes. The key aspect of the approach is to parameterise the 3D geometry through the blade loading distribution used in 3D inverse design code TURBOdesign1, which results in ability to access large part of design space with very few design parameters. The Design of Experiments method is used to generate a number of geometries which are then analysed by 3D CFD code STAR-CCM+ and 3D FEA code Abaqus. Different performance parameters related to aerodynamics (efficiency, stable operating range etc) and structural integrity (maximum principal stress, etc) are then evaluated. The data is then used to create a response surface. The validity and accuracy of the response surface is evaluated by CFD and FEA and then once confirmed a Multi-objective Genetic Algorithm is run on the response surface to explore the trade-offs between different design parameters, such as peak efficiency, stable operating range and mechanical stress. In this paper the methodology is applied to the redesign of the well-known Eckardt centrifugal compressor impeller.

scholarly journals Sensitivity analysis of timber-concrete composite structures

2018 ◽  
Vol 16 (1) ◽  
pp. 125-134
Author(s):  
Nikola Velimirovic ◽  
Dragoslav Stojic
Keyword(s):  
Sensitivity Analysis ◽  
Composite Structures ◽  
Rank Order ◽  
Equivalent Stress ◽  
Latin Hypercube Sampling ◽  
Simulation Method ◽  
Design Parameters ◽  
Model Parameters ◽  
Design And Optimization ◽  
Stochastic Sensitivity Analysis

The sensitivity analysis could be defined as a study of how the variability of the output parameter of the considered model can be distributed to its sources, actually, on the variability of the various input model parameters. It helps to identify the most important design parameters of a particular structure and to focus on them during the design and optimization process. This paper is focused on the application of stochastic sensitivity analysis of maximum equivalent stress and maximum mid-span deflection of timber-concrete composite beam. All input parameters were considered to be random variables. Latin Hypercube Sampling numerical simulation method was employed. The estimation of the sensitivity was derived from Spearman rank-order correlation coefficient.

Optimization of High Speed Centrifugal Compressor for a Micro Gas Turbine Based on CFD and FEM Analysis

2010 ◽  
Author(s):  
Hong-liang Wang ◽  
Guang Xi
Keyword(s):  
Gas Turbine ◽  
Centrifugal Compressor ◽  
Structural Reliability ◽  
Aerodynamic Performance ◽  
Design Parameters ◽  
Blade Angle ◽  
Original Design ◽  
Micro Gas Turbine ◽  
Back Face ◽  
Compressor Impeller

The centrifugal compressor impeller plays a significant role in the micro gas turbine. Its aerodynamic performance and structural reliability has great impact on the gas turbine system. Its aerodynamic performance and structural reliability are determined by blade design parameters and impeller back face design parameters. This paper presents a process of optimizing a centrifugal compressor impeller during the development of 100kW class micro gas turbine. Predicted by a 3D Navier-Stokes solver the aerodynamic performance is mainly affected by meridian contour and blade angle β distribution. The stress is calculated by means of a finite element analysis method and controlled by blade angle β distribution and thickness distribution at the hub. The requirement of high efficiency is met by using genetic algorithm and artificial neural network. Then the impeller back face profile is parameterized and optimized to decrease the stress of the impeller. The isentropic efficiency of the compressor is increased by 1% and the blade stress is reduced by 10% as compared with the original design. The results show that it is possible to reduce the centrifugal stress in the impeller without penalizing the aerodynamic performance through the optimization method.

Sensitivity analysis and optimization of a CO2 centrifugal compressor impeller with a vaneless diffuser

2021 ◽  
Author(s):  
Leandro Oliveira Salviano ◽  
Elóy Esteves Gasparin ◽  
Vitor Cesar N. Mattos ◽  
Bruno Barbizan ◽  
Fábio Saltara ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Centrifugal Compressor ◽  
Vaneless Diffuser ◽  
Compressor Impeller

scholarly journals Geometric Design-based Dimensional Synthesis of a Novel Metamorphic Multi-fingered Hand with Maximal Workspace

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Wei An ◽  
Jun Wei ◽  
Xiaoyu Lu ◽  
Jian S. Dai ◽  
Yanzeng Li
Keyword(s):  
Geometric Design ◽  
Practical Significance ◽  
Design Parameters ◽  
Control Algorithms ◽  
Discretization Method ◽  
Dimensional Synthesis ◽  
Symmetrical Structure ◽  
Design And Optimization ◽  
Total Length

AbstractCurrent research on robotic dexterous hands mainly focuses on designing new finger and palm structures, as well as developing smarter control algorithms. Although the dimensional synthesis of dexterous hands with traditional rigid palms has been carried out, research on the dimensional synthesis of dexterous hands with metamorphic palms remains insufficient. This study investigated the dimensional synthesis of a palm of a novel metamorphic multi-fingered hand, and explored the geometric design for maximizing the precision manipulation workspace. Different indexes were used to value the workspace of the metamorphic hand, and the best proportions between the five links of the palm to obtain the optimal workspace of the metamorphic hand were explored. Based on the fixed total length of the palm member, four nondimensional design parameters that determine the size of the palm were introduced; through the discretization method, the influence of the four design parameters on the workspace of the metamorphic hand with full-actuated fingers and under-actuated fingers was analyzed. Based on the analysis of the metamorphic multi-fingered hand, the symmetrical structure of the palm was designed, resulting in the largest workspace of the multi-fingered hand, and proved that the metamorphic palm has a massive upgrade for the workspace of underactuated fingers. This research contributed to the dimensional synthesis of metamorphic dexterous hands, with practical significance for the design and optimization of novel metamorphic hands.

scholarly journals Structural Response of a Single-Stage Centrifugal Compressor to Fluid-Induced Excitations at Low-Flow Operating Condition: Experimental and Numerical Study

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4292
Author(s):  
Kirill Kabalyk ◽  
Andrzej Jaeschke ◽  
Grzegorz Liśkiewicz ◽  
Michał Kulak ◽  
Tomasz Szydłowski ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Numerical Study ◽  
Structural Response ◽  
Flow Coefficient ◽  
Low Flow ◽  
Dynamic Strain ◽  
Duct Acoustics ◽  
Numerical Noise ◽  
Partial Load ◽  
Compressor Impeller

The article describes an assessment of possible changes in constant fatigue life of a medium flow-coefficient centrifugal compressor impeller subject to operation at close-to-surge point. Some aspects of duct acoustics are additionally analyzed. The experimental measurements at partial load are presented and are primarily used for validation of unidirectionally coupled fluid-structural numerical model. The model is based on unsteady finite-volume fluid-flow simulations and on finite-element transient structural analysis. The validation is followed by the model implementation to replicate the industry-scale loads with reasonably higher rotational speed and suction pressure. The approach demonstrates satisfactory accuracy in prediction of stage performance and unsteady flow field in vaneless diffuser. The latter is deduced from signal analysis relying on continuous wavelet transformations. On the other hand, it is found that the aerodynamic incidence losses at close-to-surge point are underpredicted. The structural simulation generates considerable amounts of numerical noise, which has to be separated prior to evaluation of fluid-induced dynamic strain. The main source of disturbance is defined as a stationary region of static pressure drop caused by flow contraction at volute tongue and leading to first engine-order excitation in rotating frame of reference. Eventually, it is concluded that the amplitude of excitation is too low to lead to any additional fatigue.

scholarly journals Design and optimization of differential capacitive micro accelerometer for vibration measurement

2021 ◽  
Vol 30 (1) ◽  
pp. 19-27
Author(s):  
Kumar Gomathi ◽  
Arunachalam Balaji ◽  
Thangaraj Mrunalini
Keyword(s):  
Software Design ◽  
Proof Mass ◽  
Vibration Measurement ◽  
Design Parameters ◽  
Mechanical Sensitivity ◽  
Design And Optimization ◽  
Capacitive Accelerometer ◽  
Cross Axis ◽  
Micro Accelerometer

Abstract This paper deals with the design and optimization of a differential capacitive micro accelerometer for better displacement since other types of micro accelerometer lags in sensitivity and linearity. To overcome this problem, a capacitive area-changed technique is adopted to improve the sensitivity even in a wide acceleration range (0–100 g). The linearity is improved by designing a U-folded suspension. The movable mass of the accelerometer is designed with many fingers connected in parallel and suspended over the stationary electrodes. This arrangement gives the differential comb-type capacitive accelerometer. The area changed capacitive accelerometer is designed using Intellisuite 8.6 Software. Design parameters such as spring width and radius, length, and width of the proof mass are optimized using Minitab 17 software. Mechanical sensitivity of 0.3506 μm/g and Electrical sensitivity of 4.706 μF/g are achieved. The highest displacement of 7.899 μm is obtained with a cross-axis sensitivity of 0.47%.

Design and optimization of bump (compression surface) for diverterless supersonic inlet

2021 ◽  
pp. 095441002110029
Author(s):  
Irsalan Arif ◽  
Hassan Iftikhar ◽  
Ali Javed
Keyword(s):  
Fitness Function ◽  
Supersonic Jet ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Least Square ◽  
Pressure Recovery ◽  
Design Parameters ◽  
Inlet System ◽  
Design And Optimization ◽  
Supersonic Inlet

In this article design and optimization scheme of a three-dimensional bump surface for a supersonic aircraft is presented. A baseline bump and inlet duct with forward cowl lip is initially modeled in accordance with an existing bump configuration on a supersonic jet aircraft. Various design parameters for bump surface of diverterless supersonic inlet systems are identified, and design space is established using sensitivity analysis to identify the uncertainty associated with each design parameter by the one-factor-at-a-time approach. Subsequently, the designed configurations are selected by performing a three-level design of experiments using the Box–Behnken method and the numerical simulations. Surrogate modeling is carried out by the least square regression method to identify the fitness function, and optimization is performed using genetic algorithm based on pressure recovery as the objective function. The resultant optimized bump configuration demonstrates significant improvement in pressure recovery and flow characteristics as compared to baseline configuration at both supersonic and subsonic flow conditions and at design and off-design conditions. The proposed design and optimization methodology can be applied for optimizing the bump surface design of any diverterless supersonic inlet system for maximizing the intake performance.

scholarly journals Comparison of Factorial and Latin Hypercube Sampling Designs for Meta-Models of Building Heating and Cooling Loads

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 512
Author(s):  
Younhee Choi ◽  
Doosam Song ◽  
Sungmin Yoon ◽  
Junemo Koo
Keyword(s):  
Latin Hypercube Sampling ◽  
Building Design ◽  
Gain Coefficient ◽  
Design Parameters ◽  
Latin Hypercube ◽  
Heating And Cooling ◽  
Factor Design ◽  
Heating Loads ◽  
Cooling Loads ◽  
Interest In Research

Interest in research analyzing and predicting energy loads and consumption in the early stages of building design using meta-models has constantly increased in recent years. Generally, it requires many simulated or measured results to build meta-models, which significantly affects their accuracy. In this study, Latin Hypercube Sampling (LHS) is proposed as an alternative to Fractional Factor Design (FFD), since it can improve the accuracy while including the nonlinear effect of design parameters with a smaller size of data. Building energy loads of an office floor with ten design parameters were selected as the meta-models’ objectives, and were developed using the two sampling methods. The accuracy of predicting the heating/cooling loads of the meta-models for alternative floor designs was compared. For the considered ranges of design parameters, window insulation (WDI) and Solar Heat Gain Coefficient (SHGC) were found to have nonlinear characteristics on cooling and heating loads. LHS showed better prediction accuracy compared to FFD, since LHS considers the nonlinear impacts for a given number of treatments. It is always a good idea to use LHS over FFD for a given number of treatments, since the existence of nonlinearity in the relation is not pre-existing information.

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