scholarly journals Parametric Design and Optimization of the Profile of Autonomous Underwater Helicopter Based on NURBS

2021 ◽  
Vol 9 (6) ◽  
pp. 668
Author(s):  
Xinyu An ◽  
Ying Chen ◽  
Haocai Huang
Keyword(s):  
Optimization Design ◽  
Cfd Simulation ◽  
Autonomous Underwater Vehicle ◽  
Optimization Procedure ◽  
Parametric Representation ◽  
Hydrodynamic Performance ◽  
Optimized Design ◽  
Parametric Curve ◽  
Design Variables ◽  
Drag Ratio

Autonomous Underwater Helicopter (AUH) is a disk-shaped Autonomous Underwater Vehicle (AUV), and it has comparative advantage of near-bottom hovering and whole-direction turn-around ability over the traditional slender AUV. An optimization design of its irregular geometric profile is essential to improve its hydrodynamic performance. A parametric representation of its profile is proposed in this paper using Non-Uniform Rational B-spline (NURBS) curve. The parametric representation of AUH profile is described with two decision variables and several data points. Based on this parametric curve, Computational Fluid Dynamics (CFD) simulation is carried out to evaluate its hydrodynamic performance with various parameters. A predication model is established over variables’ design space using Kriging surrogate model with CFD simulation results and a Genetic Algorithm (GA) procedure is conducted to find optimal design variables, which can produce an optimum lift-drag ratio. CFD verification results confirm that AUH profile with optimized design variables can increase its lift-drag ratio by 2.11 times compared with that of non-optimized ones. It demonstrates that the parametric representation and optimization procedure of AUH profile proposed in this paper is feasible, and it has a great potential in improving AUH’s performance.

Optimization Research on Dynamic Balance of Spatial Engine under Limiting Shaking Moment

2009 ◽  
Vol 626-627 ◽  
pp. 693-698
Author(s):  
Yong Yong Zhu ◽  
S.Y. Gao
Keyword(s):  
Mathematical Model ◽  
Objective Function ◽  
Kinetic Analysis ◽  
Optimization Design ◽  
Design Method ◽  
Dynamic Balance ◽  
Optimized Design ◽  
Design Variables ◽  
The Mathematical Model ◽  
Shaking Moment

Dynamic balance of the spatial engine is researched. By considering the special wobble-plate engine as the model of spatial RRSSC linkages, design variables on the engine structure are confirmed based on the configuration characters and kinetic analysis of wobble-plate engine. In order to control the vibration of the engine frame and to decrease noise caused by the spatial engine, objective function is choosed as the dimensionless combinations of the various shaking forces and moments, the restriction condition of which presents limiting the percent of shaking moment. Then the optimization design is investigated by the mathematical model for dynamic balance. By use of the optimization design method to a type of wobble-plate engine, the optimization process as an example is demonstrated, it shows that the optimized design method benefits to control vibration and noise on the engines and improve the performance practically and theoretically.

scholarly journals Study on the Motion Stability of the Autonomous Underwater Helicopter

2022 ◽  
Vol 10 (1) ◽  
pp. 60
Author(s):  
Yuan Lin ◽  
Jin Guo ◽  
Haonan Li ◽  
Hai Zhu ◽  
Haocai Huang ◽  
...  
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Angle Of Attack ◽  
Vertical Movement ◽  
Plane Motion ◽  
Hydrodynamic Performance ◽  
Scale Model ◽  
Motion Stability ◽  
Movement Stability ◽  
Stability Indexes ◽  
Drag Ratio

The hydrodynamic performance of a novel hovering autonomous underwater vehicle, the autonomous underwater helicopter (AUH), with an original disk-shaped hull (HG1) and an improved fore–aft asymmetric hull (HG3), is investigated by means of computational fluid dynamics with the adoption of overlapping mesh method. The hydrodynamic performance of the two hull shapes in surge motion with variation of the angle of attack is compared. The results show that HG3 has less resistance and higher motion stability compared to HG1. With the angle of attack reaching 10 degrees, both HG1 and HG3 achieve the maximum lift-to-drag ratio, which is higher for HG3 compared to HG1. Furthermore, based on the numerical simulation of the plane motion mechanism test (PMM) and according to Routh’s stability criterion, the horizontal movement and vertical movement stability indexes of HG1 and HG3 (GHHG1=1.0, GVHG1=49.7, GHHG2=1.0, GVHG3=2.1) are obtained, which further show that the AUH has better vertical movement stability than the torpedo-shaped AUV. Furthermore, the scale model tail velocity experiment indirectly shows that HG3 has better hydrodynamic performance than HG1.

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.

Genetic algorithm-based optimization design method of the Formula SAE racing car’s rear wing

2017 ◽  
Vol 232 (7) ◽  
pp. 1255-1269 ◽  
Author(s):  
Hui Wang ◽  
Qiuyang Bai ◽  
Xufei Hao ◽  
Lin Hua ◽  
Zhenghua Meng
Keyword(s):  
Genetic Algorithm ◽  
Optimization Design ◽  
Design Method ◽  
Optimal Solution ◽  
Optimization Procedure ◽  
Formula Sae ◽  
Design Variables ◽  
Rear Wing ◽  
Sample Points ◽  
Lift And Drag

The aerodynamic devices play an important role on the performance of the Formula SAE racing car. The rear wing is the most significant and popular element, which offers primary down force and optimizes the wake. In traditional rear wing optimization, the optimization variables are first selected, and separately enumerated according to the analyzing experience of the racing car’s external flow field, and thus the optimal design is chosen by comparison. This method is complicated, and even might lose some key sample points. In this paper, the attack angle of the rear wing and the relative position parameters are set as design variables; then the design variables’ combination is determined by the DOE experimental design method. The aerodynamic lift and drag of the racing car for these variables’ combinations are obtained by the computational fluid dynamics method. With these sample points, the approximation model is produced by the response surface method. For the sake of gaining the best lift to drag ( FL/ FD) ratio, i.e. maximum down force and the minimum drag force, the optimal solution is found by the genetic algorithm. The result shows that the established optimization procedure can optimize the rear wing’s aerodynamic characteristic on the racing car effectively and have application values in the practical engineering.

Reliability-based design optimization of 3D orthogonal woven composite automobile shock tower

2021 ◽  
pp. 002199832110476
Author(s):  
Zhao Liu ◽  
Lei Zhang ◽  
Ping Zhu ◽  
Mushi Li
Keyword(s):  
Design Optimization ◽  
Composite Structures ◽  
Optimization Design ◽  
Optimization Procedure ◽  
Woven Composite ◽  
Reliability Based Design Optimization ◽  
Multi Scale ◽  
Reliability Based Design ◽  
Design Variables ◽  
3D Orthogonal Woven

Three-dimensional orthogonal woven composites are noted for their excellent mechanical properties and delamination resistance, so they are expected to have promising prospects in lightweight applications in the automobile industry. The multi-scale characteristics and inherent uncertainty of design variables pose great challenges to the optimization procedure for 3D orthogonal woven composite structures. This paper aims to propose a reliability-based design optimization method for guidance on the lightweight design of 3D orthogonal woven composite automobile shock tower, which includes design variables from material and structure. An analytical model was firstly set up to accurately predict the elastic and strength properties of composites. After that, a novel optimization procedure was established for the multi-scale reliability optimization design of composite shock tower, based on the combination of Monte Carlo reliability analysis method, Kriging surrogate model, and particle swarm optimization algorithm. According to the results, the optimized shock tower meets the requirements of structural performance and reliability, with a weight reduction of 37.83%.

Multiple Objective Preform Die Shape Optimization Design for Controlling Forging’s Shape and Deforming Force during Forging Process

2011 ◽  
Vol 306-307 ◽  
pp. 1504-1507 ◽  
Author(s):  
Xin Hai Zhao ◽  
Guo Qun Zhao ◽  
Xiao Hui Huang ◽  
Yi Guo Luan
Keyword(s):  
Shape Optimization ◽  
Objective Function ◽  
Optimization Design ◽  
Control Point ◽  
Optimization Procedure ◽  
Multiple Objective ◽  
Forging Process ◽  
Weighted Sum Method ◽  
Design Variables ◽  
The Cost

In order to decrease the cost of the material and energy during the forging process, multiple preform die shape optimization design was carried out in this paper. Based on the FEM, a sensitivity analysis method was used to perform the optimization procedure. The shape of the forging and deforming force of the final forging was used to express the cost of material and energy respectively. Using the weighted sum method, the total objective function was gotton. The coordinates of the control point of the B-spline used to represent the preform die shape was determined as the optimization design variable. The sensitivity equations of the total objective function with respect to the design variables was developed. The multiple objective perform design optimization software was developed by FORTRAN language. And then, the preform die shape of an H-shaped forging process is optimized. The total objective function, sub-objective function, the shape of the preform die and the final forging during the optimization were given. After the optimiztion, a near net shape forging was obtained. At the same time, the deforming force decreased. The optimization results are very satisfactory.

Simulation Study for Optimization Design on Vertical Axis Wind Turbine blades

2019 ◽  
Vol 3 (1) ◽  
pp. 136-145
Author(s):  
Arie S. Pangemanan ◽  
Houtman P. Siregar ◽  
Maman Suryaman
Keyword(s):  
Wind Energy ◽  
Wind Turbine ◽  
Optimization Design ◽  
Cfd Simulation ◽  
Turbine Blades ◽  
Angle Of Attack ◽  
Vertical Axis ◽  
Evaluation Study ◽  
Vertical Axis Wind Turbine ◽  
Drag Ratio

In this article is conducted research to harness wind energy which is firstly generated by vehicle / truck that is runing on the public road highway. To take advantage of wind energy of the moving truck is designed, otherwise advisor had some ideas during the proposal defense change into fixed vertical axis wind turbine. The purpose of this evaluation study is to get optimization for the design blades of the vertical axis fixed wind turbine and finding the best blades installed and angle of attack will result in highest lift/drag ratio. While other test parameters such as air pressure, wind speed and others are held constant. In this evaluation study the angle of attack are used ranging begin from 45 and until 90 degrees. Evaluation result showed that the best blades install and angle of attack that gives the best lift/drag ratio is 5 blades at AoA ninety degree. Blades diameter of the designed wind turbine are 0.35 m and the number of blades which is the best in analytical of CFD techniques in the designed wind turbine are five pieces. The speed of the wind which is used to test the blades is 8 m/s on turbine rotation 80 rpm. The evaluation study has suceeded to do parametric optimization of the turbine blades. The optimised blades have been ready to re-designed assamble with another componens of the wind turbine to construct the prototype but there some problems / handicaps during the changes the prootype of turbine from movable to fixed wind turbine. The assambled vertical axial wind turbine postponed to further be tested in order to know its performance. CFD simulation has been performed with ten different VAWT designed models. Moving mesh and fluid flow simulation have been developed in CFD software FLUENT. The findings of these numerical simulations provided pressure contour, velocity contour, C D or C L

Buckling Behavior of Optimal Laminated Composite Cylindrical Shells Subjected to Axial Compression and External Pressure

2011 ◽  
Vol 121-126 ◽  
pp. 48-54 ◽  
Author(s):  
Behzad Abdi ◽  
Hamid Mozafari ◽  
Ayob Amran ◽  
Roya Kohandel ◽  
Ali Alibeigloo
Keyword(s):  
Axial Compression ◽  
Optimization Design ◽  
Cylindrical Shells ◽  
Laminated Composite ◽  
Optimization Procedure ◽  
Imperialist Competitive Algorithm ◽  
External Pressure ◽  
Design Variables ◽  
Buckling Behavior ◽  
Composite Cylindrical Shells

In this study, the buckling behavior of optimum laminated composite cylindrical shells subjected to axial compression and external pressure are studied. The cylindrical shells are composed of multi orthotropic layers that the principal axis gets along with the shell axis (x). The number of layers and the fiber orientation of layers are selected as optimization design variables with the aim to find the optimal laminated composite cylindrical shells. The optimization procedure was formulated with the objective of finding the highest buckling pressure. The Genetic Algorithm (GA) and Imperialist Competitive Algorithm (ICA) are two optimization algorithms that are used in this optimization procedure and the results were compared. Also, the effect of materials properties on buckling behavior was analyzed and studied.

scholarly journals Structural Optimization Design of Ship Lock Heads on Soft Soil considering Time-Varying Effects of the Structure and Foundation

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Jiawei Bai ◽  
Chao Su ◽  
Heng Zhang ◽  
Shaopei Hu
Keyword(s):  
Structural Optimization ◽  
Optimization Design ◽  
Soft Soil ◽  
Optimization Procedure ◽  
Optimized Design ◽  
Time Varying ◽  
The Maximum Principle ◽  
Hybrid Particle Swarm Optimization ◽  
Whale Optimization ◽  
Ship Lock

Over time, the uneven settlements of the structure and foundation are prominent in constructing ship lock heads on soft soil. These deformations endanger the safety of ship lock heads during construction. This research aimed to establish the ship lock head’s structural optimization procedure on soft soil, considering the time-varying effects of the structure and foundation. By comprehensively considering the linear viscoelastic creep of concrete and the elastoplastic consolidation characteristic of soft soil, a perfect time-dependent analysis method for the lock head on soft soil was proposed. Furthermore, a hybrid particle swarm optimization, enhanced whale optimization, and differential evolution (PSO-EWOA-DE) algorithm was proposed to optimize thirty-four design variables of a lock head. With the minimal volume of the lock head as the optimization objective, the finite element model was established. In the optimization process, three types of constraints were evaluated. The result showed that the optimized design could reduce 10.45% of structure volume. Through comparing and analysing the maximum principle stresses and vertical displacements of the lock head before and after optimization, some conclusions were drawn. The optimization procedure proposed in this paper provides a new perspective for the structural optimization of hydraulic structures on soft soil.

scholarly journals Airfoil Optimization Design Based on the Pivot Element Weighting Iterative Method

Algorithms ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 163 ◽  
Author(s):  
Xinqiang Liu ◽  
Weiliang He
Keyword(s):  
Optimization Design ◽  
Rbf Neural Network ◽  
Latin Hypercube Sampling ◽  
Coefficient Matrix ◽  
Aerodynamic Optimization ◽  
Airfoil Optimization ◽  
Design Variables ◽  
Aerodynamic Performances ◽  
Optimal Latin Hypercube Sampling ◽  
Drag Ratio

Class function/shape function transformation (CST) is an advanced geometry representation method employed to generate airfoil coordinates. Aiming at the morbidity of the CST coefficient matrix, the pivot element weighting iterative (PEWI) method is proposed to improve the condition number of the ill-conditioned matrix in the CST. The feasibility of the PEWI method is evaluated by using the RAE2822 and S1223 airfoil. The aerodynamic optimization of the S1223 airfoil is conducted based on the Isight software platform. First, the S1223 airfoil is parameterized by the CST with the PEWI method. It is very significant to confirm the range of variables for the airfoil optimization design. So the normalization method of design variables is put forward in the paper. Optimal Latin Hypercube sampling is applied to generate the samples, whose aerodynamic performances are calculated by the numerical simulation. Then the Radial Basis Functions (RBF) neural network model is trained by these aerodynamic performance data. Finally, the multi-island genetic algorithm is performed to achieve the maximum lift-drag ratio of S1223. The results show that the robustness of the CST can be improved. Moreover, the lift-drag ratio of S1223 increases by 2.27% and the drag coefficient decreases by 1.4%.

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