Innovative Turbine Stator Well Design Using a Kriging-Assisted Optimization Method

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Julien Pohl ◽  
Harvey M. Thompson ◽  
Ralf C. Schlaps ◽  
Shahrokh Shahpar ◽  
Vincenzo Fico ◽  
...  
Keyword(s):  
Engine Performance ◽  
Internal Flow ◽  
Optimization Method ◽  
Optimized Design ◽  
Element Analysis ◽  
Baseline Design ◽  
Turbine Stator ◽  
Air Temperatures ◽  
Design Variables ◽  
Deflector Plate

At present, it is a common practice to expose engine components to main annulus air temperatures exceeding the thermal material limit in order to increase the overall engine performance and to minimize the engine specific fuel consumption. To prevent overheating of the materials and thus the reduction of component life, an internal flow system is required to cool and protect the critical engine parts. Previous studies have shown that the insertion of a deflector plate in turbine cavities leads to a more effective use of reduced cooling air, since the coolant is fed more effectively into the disk boundary layer. This paper describes a flexible design parameterization of an engine representative turbine stator well geometry with stationary deflector plate and its implementation within an automated design optimization process using automatic meshing and steady-state computational fluid dynamics (CFD). Special attention and effort is turned to the flexibility of the parameterization method in order to reduce the number of design variables to a minimum on the one hand, but increasing the design space flexibility and generality on the other. Finally, the optimized design is evaluated using a previously validated conjugate heat transfer method (by coupling a finite element analysis (FEA) to CFD) and compared against both the nonoptimized deflector design and a reference baseline design without a deflector plate.

Turbine Stator Well Cooling: Improved Geometry Benefits

2015 ◽  
Author(s):  
Julien Pohl ◽  
Jeffrey A. Dixon ◽  
Vincenzo Fico
Keyword(s):  
Experimental Data ◽  
Engine Performance ◽  
Prediction Method ◽  
Internal Flow ◽  
Element Analysis ◽  
Turbine Stator ◽  
Structured Mesh ◽  
Deflector Plate ◽  
Side Flow ◽  
Block Structured

Nowadays, it is common practice to expose engine components to air temperatures exceeding the thermal material limit in order to increase the overall engine performance and to minimise the engine specific fuel consumption (SFC). To avoid the overheating of the materials and thus the reduction of the component life, an internal flow system is designed to cool the critical engine parts and to protect them. As the coolant flow is bled from the compressor and not used for the combustion the amount of coolant is aimed to be minimised as much as possible to preserve the overall engine performance. Experiments as well as numerical simulations have shown that with the use of a deflector plate, the cooling flow is fed more directly into the disc boundary layer, allowing more effective use of less cooling air, leading to an improved engine efficiency. In this paper, the benefits of the use of a stationary deflector plate inside a turbine stator well (TSW) are presented. So far unpublished experimental data obtained from tests carried out in a two-stage turbine rig are presented. The main objective of this research has been to produce reliable methods for predicting the effects of geometry changes in this type of engine cavity, with a view to optimising the cooling flows required to maintain component integrity and life. Therefore, a numerical methodology is presented and validated against the experimental data. Steady and unsteady computational fluid dynamics (CFD) calculations of a sector model are used to determine whether fluid side flow distributions and heat transfer can be adequately represented, as well as to expose the limits of these approaches. The main annulus geometry is meshed with a multi-block structured mesh using the in-house code PADRAM. The cavity geometry is meshed once with a multi-block structured mesh using the commercial tool ANSYS ICEM and once with an unstructured mesh using the in-house code PADRAM. The CFD calculations are carried out with the commercial code FLUENT from ANSYS as well as the in-house code HYDRA. Finally, for the cavity with the deflector plate and no net ingestion, the steady state solution of the CFD is coupled to a finite element analysis (FEA) model created in the in-house code SC03 in order to take the conjugate effects into account. With this method the final non-adiabatic flow field inside the cavity as well as the final metal temperatures are obtained, which again are compared against thermocouple measured data in order to evaluate the accuracy of the numerical prediction method.

Structural Deflection's Impact in Turbine Stator Well Heat Transfer

2016 ◽  
Vol 139 (4) ◽  
Author(s):  
Julien Pohl ◽  
Harvey M. Thompson ◽  
Antonio Guijarro Valencia ◽  
Gregorio López Juste ◽  
Vincenzo Fico ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Test Data ◽  
Internal Flow ◽  
Radial Component ◽  
Element Analysis ◽  
Turbine Stator ◽  
Air Temperatures ◽  
Air Supply ◽  
Commercial Solver ◽  
The Impact

In the most evolved designs, it is common practice to expose engine components to main annulus air temperatures exceeding the thermal material limit in order to increase the overall performance and to minimize the engine-specific fuel consumption (SFC). To prevent overheating of the materials and thus the reduction of the component life, an internal flow system is required to cool the critical engine parts and to protect them. This paper shows a practical application and extension of the methodology developed during the five-year research program, main annulus gas path interaction (MAGPI). Extensive use was made of finite element analysis (FEA (solids)) and computational fluid dynamics (CFD (fluid)) modeling techniques to understand the thermomechanical behavior of a dedicated turbine stator well cavity rig, due to the interaction of cooling air supply with the main annulus. Previous work based on the same rig showed difficulties in matching predictions to thermocouple measurements near the rim seal gap. In this investigation, two different types of turbine stator well geometries were analyzed, where—in contrast to previous analyses—further use was made of the experimentally measured radial component displacements during hot running in the rig. The structural deflections were applied to the existing models to evaluate the impact inflow interactions and heat transfer. Additionally, to the already evaluated test cases without net ingestion, cases simulating engine deterioration with net ingestion were validated against the available test data, also taking into account cold and hot running seal clearances. 3D CFD simulations were conducted using the commercial solver fluent coupled to the in-house FEA tool SC03 to validate against available test data of the dedicated rig.

Solid Mechanics Based Design and Optimization for Support Structure Generation in Stereolithography Based Additive Manufacturing

2015 ◽  
Author(s):  
Guanglei Zhao ◽  
Chi Zhou ◽  
Sonjoy Das
Keyword(s):  
Additive Manufacturing ◽  
Solid Mechanics ◽  
Search Algorithm ◽  
Pso Algorithm ◽  
Optimization Method ◽  
Optimized Design ◽  
Support Structures ◽  
Support Structure ◽  
Element Analysis ◽  
Structure Generation

Support structures are typically required to hold parts in place in various additive manufacturing processes. Design of support structure includes identifying both anchor locations and geometries. Extensive work has been done to optimize the anchor locations to reliably keep part in position, and minimize the contacting area as well as the total volume of the support structures. However, relatively few studies have been focused on the mechanical property analysis of the structure. In this paper, we proposed a novel design optimization method to identify the anchor geometry based on solid mechanics theory. Finite element analysis method is utilized to study the stress distribution on both the support structure and main part. Particle Swarm Optimization (PSO) algorithm with a novel constraining handling strategy is employed to optimize the design model. A gradient descent local search algorithm is utilized to quickly locate the global solution in the vicinity explored by PSO. The developed optimization framework is deployed on a bottom-up projection based Stereolithography process. The experimental results show that the optimized design can efficiently reduce the material used on support structure and marks left on the part.

The Spindle Structural Optimization Design of HTC3250µn NC Machine Tool Based on ANSYS

2012 ◽  
Vol 457-458 ◽  
pp. 60-64 ◽  
Author(s):  
Hua Long Xie ◽  
Hui Min Guo ◽  
Qing Bao Wang ◽  
Yong Xian Liu
Keyword(s):  
Machine Tool ◽  
Optimization Design ◽  
Optimization Method ◽  
Optimized Design ◽  
Nc Machine Tool ◽  
Mathematical Mode ◽  
Design Variables ◽  
Before And After ◽  
Nc Machine ◽  
Important Significance

The optimization of spindle has important significance. The optimization method based on ANSYS is introduced and spindle mathematical mode of HTC3250µn NC machine tool is given. By scanning of design variables, the main optimized design variables are determined. The single objective and multi-objective optimizations are done. In the end, the main size comparison of spindle before and after optimization is given.

scholarly journals Analysis-Driven Design Optimization of a SMA-Based Slat-Cove Filler for Aeroacoustic Noise Reduction

2013 ◽  
Author(s):  
William Scholten ◽  
Darren Hartl ◽  
Travis Turner
Keyword(s):  
Structural Response ◽  
Leading Edge ◽  
Optimized Design ◽  
Analysis Model ◽  
Element Analysis ◽  
Airframe Noise ◽  
Aeroacoustic Noise ◽  
Aerodynamic Pressure ◽  
Configuration Change ◽  
Design Variables

Airframe noise is a significant component of environmental noise in the vicinity of airports. The noise associated with the leading-edge slat of typical transport aircraft is a prominent source of airframe noise. Previous work suggests that a slat-cove filler (SCF) may be an effective noise treatment. Hence, development and optimization of a practical slat-cove-filler structure is a priority. The objectives of this work are to optimize the design of a functioning SCF that incorporates superelastic shape memory alloy (SMA) materials as flexures that permit the deformations involved in the configuration change. The goal of the optimization is to minimize the actuation force needed to retract the slat-SCF assembly while satisfying constraints on the maximum SMA stress and on the SCF deflection under static aerodynamic pressure loads, while also satisfying the condition that the SCF self-deploy during slat extension. A finite element analysis model based on a physical bench-top model is created in Abaqus such that automated iterative analysis of the design could be performed. In order to achieve an optimized design, several design variables associated with the current SCF configuration are considered, such as the thicknesses of SMA flexures and the dimensions of various components, SMA and conventional. Design of experiment (DOE) studies are performed to investigate structural response to an aerodynamic pressure load and to slat retraction and deployment. DOE results are then used to inform the optimization process, which determines a design minimizing actuator forces while satisfying the required constraints.

Structural Deflection’s Impact in Turbine Stator Well Heat Transfer

2016 ◽  
Author(s):  
Julien Pohl ◽  
Harvey Thompson ◽  
Antonio Guijarro Valencia ◽  
Gregorio López Juste ◽  
Vincenzo Fico ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Test Data ◽  
Internal Flow ◽  
Research Programme ◽  
Turbine Stator ◽  
Air Temperatures ◽  
Air Supply ◽  
Flow Interactions ◽  
Commercial Solver ◽  
The Impact

In the most evolved designs, it is common practice to expose engine components to main annulus air temperatures exceeding the thermal material limit in order to increase the overall performance and to minimise the engine specific fuel consumption (SFC). To prevent overheating of the materials and thus the reduction of the component life, an internal flow system is required to cool the critical engine parts and to protect them. This paper shows a practical application and extension of the methodology developed during the five year research programme MAGPI. Extensive use was made of FEA (solids) and CFD (fluid) modelling techniques to understand the thermo-mechanical behaviour of a dedicated turbine stator well cavity rig, due to the interaction of cooling air supply with the main annulus. Previous work based on the same rig showed difficulties in matching predictions to thermocouple measurements near the rim seal gap. In this investigation, two different types of turbine stator well geometries were analysed, where further use was made of existing measurements of hot running seal clearances in the rig. The structural deflections were applied to the existing models to evaluate the impact in flow interactions and heat transfer. Additionally to the already evaluated test cases without net ingestion, cases simulating engine deterioration with net ingestion were validated against the available test data, also taking into account cold and hot running seal clearances. 3D CFD simulations were conducted using the commercial solver FLUENT coupled to the in-house FEA tool SC03 to validate against available test data of the dedicated rig.

Optimized Design of the Horn of Ultrasonic Roll Welding

2012 ◽  
Vol 482-484 ◽  
pp. 2223-2226 ◽  
Author(s):  
Kuen Ming Shu ◽  
Yu Guang Li ◽  
Chun Chi Chan ◽  
Jonq Bor Kuan
Keyword(s):  
Random Search ◽  
Optimal Solution ◽  
Optimization Method ◽  
Resonant Mode ◽  
Mode Frequency ◽  
Optimized Design ◽  
Solar Panels ◽  
Design Variables ◽  
Local Optimal Solution ◽  
The Impact

Previous studies on the amplitude horn only calculated sizes in consistent with the axial resonant mode frequency and disc bending resonant mode frequency without considering the overall stress and the amplitude of the disc’s outer ring. The resonant frequency of the amplitude horn cannot occur around 35 kHz. Such a design results in the inability to weld and may damage solar panels or lead to poor welding quality. Using the optimization method to address these problems, the proposed design process in this study is to conduct sensitivity analysis by the gradient method to understand the impact of design variables on the objective function for the selection of design variables. Then, this study applied the random search method to find out the feasible design of arrays to optimize the structure of two arrays closest to the design objective by the full factorial experiment method to ensure to get the global optimal solution rather than the local optimal solution. Finally, by design examples, this study used the sub-problem approximation method to search the optimized solution and compared the differences of the two methods, in order to confirm whether the objective of optimized design of amplitude horn had been achieved.

Optimization Framework Using Surrogate Model for Aerodynamically Improved 3D Turbine Blade Design

2014 ◽  
Author(s):  
Sanga Lee ◽  
Saeil Lee ◽  
Kyu-Hong Kim ◽  
Dong-Ho Lee ◽  
Young-Seok Kang ◽  
...  
Keyword(s):  
Surrogate Model ◽  
Design Space ◽  
Computational Cost ◽  
Three Dimensional ◽  
Experimental Point ◽  
Optimized Design ◽  
Kriging Method ◽  
Baseline Design ◽  
Design Variables ◽  
Nonlinear Design

In simple optimization problem, direct searching methods are most accurate and practical enough. However, for more complicated problem which contains many design variables and demands high computational costs, surrogate model methods are recommendable instead of direct searching methods. In this case, surrogate models should have reliability for not only accuracy of the optimum value but also globalness of the solution. In this paper, the Kriging method was used to construct surrogate model for finding aerodynamically improved three dimensional single stage turbine. At first, nozzle was optimized coupled with base rotor blade. And then rotor was optimized with the optimized nozzle vane in order. Kriging method is well known for its good describability of nonlinear design space. For this reason, Kriging method is appropriate for describing the turbine design space, which has complicated physical phenomena and demands many design variables for finding optimum three dimensional blade shapes. To construct airfoil shape, Prichard topology was used. The blade was divided into 3 sections and each section has 9 design variables. Considering computational cost, some design variables were picked up by using sensitivity analysis. For selecting experimental point, D-optimal method, which scatters each experimental points to have maximum dispersion, was used. Model validation was done by comparing estimated values of random points by Kriging model with evaluated values by computation. The constructed surrogate model was refined repeatedly until it reaches convergence criteria, by supplying additional experimental points. When the surrogate model satisfies the reliability condition and developed enough, finding optimum point and its validation was followed by. If any variable was located on the boundary of design space, the design space was shifted in order to avoid the boundary of the design space. This process was also repeated until finding appropriate design space. As a result, the optimized design has more complicated blade shapes than that of the baseline design but has higher aerodynamic efficiency than the baseline turbine stage.

Analysis of 24Slot wound field salient rotor switched-flux machine based on 2D-FEA

2016 ◽  
Vol 13 (5) ◽  
pp. 381-385 ◽  
Author(s):  
Faisal Khan ◽  
Erwan Sulaiman ◽  
Hassan Ali Soomro ◽  
Fairoz Omar ◽  
Zarafi Ahmad
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Optimization Method ◽  
Optimized Design ◽  
Flux Linkage ◽  
Element Analysis ◽  
Content Type ◽  
Three Phase ◽  
Rotor Poles ◽  
Dimensional Finite Element

Purpose The paper aims to propose and compare two new structures of a three-phase wound field salient rotor (WFSR) switched-flux motor (SFM) with 24 stator slots and 10 or 14 rotor poles, respectively, for high-speed operation. Design/methodology/approach The paper outlines the motor general construction and design concept of proposed machines. Flux linkage, average torque, rotor mechanical strength and torque–speed characteristics of both machines were analyzed and compared by two-dimensional finite element analysis (2D-FEA). Deterministic optimization method was adopted to enhance the characteristics of 24Slot-10Pole WFSR SFM. Findings The paper provides simulation results and discusses how 24Slot-10Pole WFSR SFM structure is superior to the 24Slot-14Pole in the aspects of flux linkage, average torque and power. It further concludes that the optimized design of 24Slot-10P has achieved 58 and 72 per cent higher average torque and power compared to initial design, as well as high average torque and power compared to 24Slot-14P design. Originality value Optimized structure of the 24Slot-10Pole WFSR SFM with non-overlapping windings has been proposed.

scholarly journals Aerodynamic and structural optimization of wind turbine blade with static aeroelastic effects

2019 ◽  
Vol 15 (1) ◽  
pp. 55-64
Author(s):  
Jie Zhu ◽  
Xiaohui Ni ◽  
Xiaomei Shen
Keyword(s):  
Structural Optimization ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Optimization Method ◽  
Wind Turbine Blade ◽  
Analysis Model ◽  
Element Analysis ◽  
Design Variables ◽  
Aeroelastic Analysis ◽  
Static Aeroelasticity

Abstract With the increasing size of wind turbine blade, the aeroelastic analysis becomes an essential step in the blade design process. The scope of this paper is to investigate the static aeroelastic effects between the fluid–structure interaction and improve the blade performances. First, the rigid and flexible blades are used to analyze the effects of static aeroelasticity on the blade aerodynamic and structural performances through a blade element momentum model coupled with 3D finite element analysis model. Based on this, a multi-objective aerodynamic and structural optimization method is proposed aiming at increasing the annual energy production and reducing blade mass, key parameters of the blade are employed as design variables, and various design requirements including strain, deflection, vibration and buckling limits are considered as constraints. Finally, a commercial 1.5 MW wind turbine blade is applied as a case study, and the optimization results show great improvements for the aerodynamic and structural performances of the blade.

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