Parametric Design and Optimization of the Impeller Geometry for an Automotive Torque Converter Using DOE Method

Author(s):  
Guangqiang Wu ◽  
Jie Chen

Design of experiment (DOE) and computational fluid dynamics (CFD) techniques are applied to obtain an optimal design of the impeller geometry for an automotive torque converter. A new parametric geometric design method of impeller is proposed by means of parametric equations and Creo software. Eleven design parameters are used to obtain the parametric model and can be represented by six parameters including impeller blade number, blade thickness, bias angle, scroll angle, inlet angle and exit angle. DOE method is used to investigate the relative importance of the six design parameters for each response (stall torque ratio and peak efficiency). The impeller bias angle is found to exert the greatest influence on stall torque ratio while the impeller exit angle has the strongest impact on the peak efficiency. Three optimized cases for the impeller geometry of an automotive torque converter are obtained based on desirability function approach. The new parametric design and optimization methods can provide fundamental guidelines for performance enhancement in the design process of impeller geometry for an automotive torque converter.

Author(s):  
Cheng Liu ◽  
Meng Guo ◽  
Wei Wei ◽  
Qingdong Yan ◽  
Pengyu Li

Abstract A lot of efforts were put into the design of torque converter blade angles and the analysis of transient flow behaviors; yet little is known about the influence of the blade thickness distribution on the performance or structural response of a torque converter. This study proposed a parameterized blade thickness design model and analyzed the effects of the blade thickness on hydrodynamic performance and structural response using fluid-structure interaction (FSI) models. Both one-way FSI model and two-way FSI model were built and evaluated against test data, and it was found that the transient two-way FSI model outperformed the steady-state FSI model in terms of both flow and structure simulations. It was found that the stall torque ratio and peak efficiency exhibited positive correlations with blade thicknesses, whereas the stall capacity constant was inversely related to blade thicknesses. Both numerical and experimental results suggested that the pump-turbine interaction induced serious flow fluctuations, and FSI simulations were required in the design process to avoid potential resonance.


Author(s):  
Jie Chen ◽  
Guangqiang Wu

Abstract Since impeller shape has great influence on hydraulic performance of a torque converter, a multi-objective optimization method based on non-dominated sorting genetic algorithm II (NSGA-II) has been used to redesign the impeller geometry. Radial basis function (RBF) is attempted to establish the surrogate models for performance responses in impeller design. A sophisticated automotive torque converter case is exemplified, which demonstrates that RBF provides a better surrogate accuracy and NSGA-II is more effective than the other methods studied. To verify the optimization results, the complete numerical characteristic curves of the torque converter with the optimized impeller are compared to the validated numerical characteristic curves of the initial torque converter. The numerical results show that the stall torque ratio and peak efficiency are increased by 3.18% and 1.4%, respectively. The results indicate a reasonable improvement in the optimal design of torque converter impeller and a higher performance using the NSGA-II method.


2021 ◽  
Author(s):  
Guang Xi ◽  
Chenxi Zhao ◽  
Yonghong Tang ◽  
Zhiheng Wang

Abstract The shrouded and unshrouded impellers are two typical kinds of impellers, which are widely utilized in centrifugal compressors of various applications. Centrifugal compressors with unshrouded impellers are generally recognized to display inferior performance to the shrouded impellers with the same geometry. In this paper, a comparative experiment shows some results inconsistent with conventional cognition. Measured performance indicates that the peak efficiency of the centrifugal compressor with an unshrouded impeller is higher than the shrouded one, where the two impellers have the same geometry of meridional profile and blade central plane, and matched the same vaneless diffuser and volute. In order to explore the causes of this divergence, the effects of factors such as blade thickness, surface roughness of components, tip clearance and sealing leakage characteristics on performance are analyzed by CFD code. Numerical results show that reasonable reduction in the blade thickness and improvement on the surface quality of the impeller could effectively increase the peak efficiency and the choke mass flow rate of the shrouded impeller. The unshrouded impeller with arbitrary blade surfaces would be deformed under the action of centrifugal force to achieve a small tip clearance during operation, and then obtains higher efficiency at design speed. The research results are helpful to evaluate the performance potential and sensitive design parameters of shrouded and unshrouded impellers.


2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Wei An ◽  
Jun Wei ◽  
Xiaoyu Lu ◽  
Jian S. Dai ◽  
Yanzeng Li

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.


2021 ◽  
Vol 30 (1) ◽  
pp. 19-27
Author(s):  
Kumar Gomathi ◽  
Arunachalam Balaji ◽  
Thangaraj Mrunalini

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%.


Author(s):  
Irsalan Arif ◽  
Hassan Iftikhar ◽  
Ali Javed

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.


2013 ◽  
Vol 791-793 ◽  
pp. 799-802
Author(s):  
Ya Ping Wang ◽  
H.R. Shi ◽  
L. Gao ◽  
Z. Wang ◽  
X.Y. Jia ◽  
...  

With the increasing of the aging of population all over the world, and With the inconvenience coming from diseases and damage, there will be more and more people using the wheelchair as a tool for transport. When it cant be short of the wheelchair in the daily life, the addition of the function will bring the elevation of the quality of life for the unfortunate. Staring with this purpose, the research designs a pickup with planetary bevel gear for the wheelchair. After determining the basic function of the wheelchair aids, the study determines the design parameters by using the knowledge of parametric design and completes the model for the system with Pro/E, on the other hand, it completes key components optimization analysis which is based on genetic algorithm optimization.


Author(s):  
Myung-Jin Choi ◽  
Min-Geun Kim ◽  
Seonho Cho

We developed a shape-design optimization method for the thermo-elastoplasticity problems that are applicable to the welding or thermal deformation of hull structures. The point is to determine the shape-design parameters such that the deformed shape after welding fits very well to a desired design. The geometric parameters of curved surfaces are selected as the design parameters. The shell finite elements, forward finite difference sensitivity, modified method of feasible direction algorithm and a programming language ANSYS Parametric Design Language in the established code ANSYS are employed in the shape optimization. The objective function is the weighted summation of differences between the deformed and the target geometries. The proposed method is effective even though new design variables are added to the design space during the optimization process since the multiple steps of design optimization are used during the whole optimization process. To obtain the better optimal design, the weights are determined for the next design optimization, based on the previous optimal results. Numerical examples demonstrate that the localized severe deviations from the target design are effectively prevented in the optimal design.


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