A Flow Path Generation Approach of Hydraulic Manifold Blocks Based on Maze and Genetic Algorithms

2011 ◽  
Vol 338 ◽  
pp. 106-110
Author(s):  
Guang Li ◽  
Wen Tie Niu ◽  
Da Wei Zhang ◽  
Wei Guo Gao
Keyword(s):  
Genetic Algorithm ◽  
Optimal Path ◽  
Three Dimensional ◽  
Automatic Generation ◽  
Flow Path ◽  
Secondary Development ◽  
Design Parameters ◽  
Initial Population ◽  
Flow Paths ◽  
Starting Point

The automatic generation of flow path is the key and most difficult task in Hydraulic Manifold Blocks (HMB) design. This paper divides the HMB layout space into grids, and sets the HMB boundaries and existing flow paths to obstacles, and the paths generated using maze algorithm are regarded as the initial population of genetic algorithm. The optimal path with the shortest path and least turnings can be obtained using genetic algorithm. The ports of flow path can be connected after the generation of technical holes based on the blind holes. The design parameters of holes, such as starting point coordinates, orientations and depths, can be obtained through a series of algorithms, and then drive the secondary development system HMBDesigner based on SolidWorks to generate three-dimensional solid model. This paper also discusses the generation method of multi-port flow path and multiple flow paths.

Automatic Three-Dimensional Optimisation of a Modern Tandem Compressor Vane

2014 ◽  
Author(s):  
R. C. Schlaps ◽  
S. Shahpar ◽  
V. Gümmer
Keyword(s):  
Pressure Ratio ◽  
Three Dimensional ◽  
Trust Region ◽  
Automatic Generation ◽  
Navier Stokes ◽  
Design Parameters ◽  
High Fidelity ◽  
Stall Margin ◽  
Design Choice ◽  
Multipoint Approximation

In order to increase the performance of a modern gas turbine, compressors are required to provide higher pressure ratio and avoid incurring higher losses. The tandem aerofoil has the potential to achieve a higher blade loading in combination with lower losses compared to single vanes. The main reason for this is due to the fact that a new boundary layer is generated on the second blade surface and the turning can be achieved with smaller separation occurring. The lift split between the two vanes with respect to the overall turning is an important design choice. In this paper an automated three-dimensional optimisation of a highly loaded compressor stator is presented. For optimisation a novel methodology based on the Multipoint Approximation Method (MAM) is used. MAM makes use of an automatic design of experiments, response surface modelling and a trust region to represent the design space. The CFD solutions are obtained with the high-fidelity 3D Navier-Stokes solver HYDRA. In order to increase the stage performance the 3D shape of the tandem vane is modified changing both the front and rear aerofoils. Moreover the relative location of the two aerofoils is controlled modifying the axial and tangential relative positions. It is shown that the novel optimisation methodology is able to cope with a large number of design parameters and produce designs which performs better than its single vane counterpart in terms of efficiency and numerical stall margin. One of the key challenges in producing an automatic optimisation process has been the automatic generation of high-fidelity computational meshes. The multi block-structured, high-fidelity meshing tool PADRAM is enhanced to cope with the tandem blade topologies. The wakes of each aerofoil is properly resolved and the interaction and the mixing of the front aerofoil wake and the second tandem vane are adequately resolved.

scholarly journals Developing the Flow Path For the K-1250-6.9/25 Turbine Unit Using the Optimal Design Methods

2021 ◽  
pp. 15-18
Author(s):  
Ihor Palkov ◽  
Sergii Palkov ◽  
Oleh Ishchenko ◽  
Olena Avdieieva
Keyword(s):  
Numerical Experiment ◽  
Cross Sections ◽  
Turbine Unit ◽  
Current Flow ◽  
Three Dimensional ◽  
Flow Path ◽  
Three Dimensional Model ◽  
Flow Paths ◽  
Intermediate Pressure ◽  
Blade System

The paper considers the main principles that are used to develop the flow paths (FP) of the high-pressure cylinders (HPC), intermediate-pressure cylinders (IPC), and low-pressure cylinders (LPC) for the K-1250-6.9/25 turbine unit. It describes approaches to the numerical experiment when designing flow paths, the advantage of which is lower labor, time and financial costs and higher informativeness compared to the physical experiment on flow paths. When designing the flow paths of high- and intermediate-pressure cylinders (HIPC), the numerical experiment is performed using the three-dimensional viscous-flow method. For this purpose, a three-dimensional model of the blade system in the flow path is built, which consists of a large number of finite volumes (elements) in the shape of hexagons, in each of which the integration of the equations of gas dynamics is performed. When developing LPC, the method of parameterization and analytical profiling of the blade crown sections is used, where the profiles are described by the curves of the fourth and fifth orders with the condition of providing the minimum value of the maximum curvature and monotonicity of variation of the three-dimensional blade geometry along height. This method allows obtaining the optimal profiles of the cross sections of the blades, which correspond to the current flow lines to the fullest extent, and minimizing the profile energy losses when the flow flows around the blades.

scholarly journals Analysis of the velocity diagrams of impellers of centrifugal compressor stages after the preliminary design

2018 ◽  
Vol 245 ◽  
pp. 04004 ◽  
Author(s):  
Aleksandr Drozdov ◽  
Alexey Rekstin
Keyword(s):  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Flow Path ◽  
Preliminary Design ◽  
Flow Paths ◽  
Design Program ◽  
Three Stages ◽  
Correct Application ◽  
Development Laboratory

Preliminary design is an important stape in the development of centrifugal compressors and compressor stages. Basically for this purpose, various recommendations on the choice of the flow path dimensions are applied. Researchers of the Research and Development Laboratory “Gas dynamics of turbomachines” prof. Yu.B. Galerkin and A.F. Rekstin analyzed and summarized the dimensions of flow paths of 124 impellers. On the basis of this analysis, formulas were proposed for choosing the flow path dimensions of the centrifugal compressor stages, which were included in the preliminary design program. The formulas used are designed for relative Mach number of 0.7 and isentropic coefficient of 1.4. The correct application of these formulas for other Mach numbers and isentropic coefficient required development of an appropriate approach and algorithm for adjusting the height of the impeller blades at the outlet. Calculations of gas-dynamic characteristics using the Universal Modeling Method showed the need for selecting a coefficient that takes into account the influence of viscosity to obtain the required pressure characteristics of the compressor stage. This problem was also solved in the program of preliminary design. To check the quality of preliminary design, the results were verified using a non-viscous quasi-three-dimensional calculation program. Three stages were designed for parameters different to those used for development of preliminary design formulas. Analysis of the velocity diagrams of the impeller blades and distribution of meridional velocities showed good results of the preliminary design.

Genetic algorithm-based compliant robot path planning: an improved Bi-RRT-based initialization method

2017 ◽  
Vol 37 (3) ◽  
pp. 261-270 ◽  
Author(s):  
Du Lin ◽  
Bo Shen ◽  
Yurong Liu ◽  
Fuad E. Alsaadi ◽  
Ahmed Alsaedi
Keyword(s):  
Genetic Algorithm ◽  
Execution Time ◽  
Optimal Path ◽  
Dynamic Environment ◽  
Initial Population ◽  
Robot Path Planning ◽  
Complex Dynamic ◽  
Content Type ◽  
Compliant Robot ◽  
Robot Path

Purpose The purpose of this paper is to improve the performance of the genetic algorithm-based compliant robot path planning (GACRPP) in complex dynamic environment by proposing an improved bidirectional rapidly exploring random tree (Bi-RRT)-based population initialization method. Design/methodology/approach To achieve GACRPP in complex dynamic environment with high performance, an improved Bi-RRT-based population initialization method is proposed. First, the grid model is adopted to preprocess the working space of mobile robot. Second, an improved Bi-RRT is proposed to create multi-cluster connections between the starting point and the goal point. Third, the backtracking method is used to generate the initial population based on the multi-cluster connections generated by the improved Bi-RRT. Subsequently, some comparative experiments are implemented where the performances of the improved Bi-RRT-based population initialization method are compared with other population initialization methods, and the comparison results of the improved genetic algorithm (IGA) combining with the different population initialization methods are shown. Finally, the optimal path is further smoothed with the help of the technique of quadratic B-spline curves. Findings It is shown in the experiment results that the improved Bi-RRT-based population initialization method is capable of deriving a more diversified initial population with less execution time and the IGA combining with the proposed population initialization method outperforms the one with other population initialization methods in terms of the length of optimal path and the execution time. Originality/value In this paper, the Bi-RRT is introduced as a population initialization method into the GACRPP problem. An improved Bi-RRT is proposed for the purpose of increasing the diversity of initial population. To characterize the diversity of initial population, a new notion of breadth is defined in terms of Hausdorff distance between different paths.

Achieve of Torpedo Shell Parameter Model Based on Secondary Development of UG

2012 ◽  
Vol 542-543 ◽  
pp. 532-536
Author(s):  
Nan Li ◽  
Yun Peng Zhao
Keyword(s):  
Design Process ◽  
Parametric Design ◽  
Three Dimensional ◽  
Secondary Development ◽  
Design Parameters ◽  
Three Dimensional Model ◽  
Three Dimensional Modeling ◽  
Modeling Software ◽  
Shell Parameter ◽  
Set Up

Torpedo shell Modeling is a very important part in the design process. However, the traditional method of torpedo shell modeling is only the GUI of CAD drawing software. If there is change in individual parameters, designers have to start again from scratch. Such method will waste of resources. This paper set up the torpedo shell parametric design process with secondary development language UG / Open API, and user-oriented menu creation tool UG / Open UIStyler of UG,which is a three-dimensional modeling software, So that designers can be directly obtained three-dimensional model of the torpedo shell needing to enter the necessary design parameters. Meanwhile the designers can save design resources, and it helps optimize the latter part of the torpedo shell design.

Three-Dimensional Design Method for Long Blades of Steam Turbines Using Fourth-Degree NURBS Surface

2010 ◽  
Author(s):  
Shigeki Senoo ◽  
Koji Ogata ◽  
Tateki Nakamura ◽  
Naoaki Shibashita
Keyword(s):  
Design Method ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Flow Path ◽  
Design Parameters ◽  
Control Points ◽  
Steam Turbines ◽  
Nurbs Surface ◽  
Fourth Degree ◽  
Nurbs Curve

A new blade design method for steam turbines using the fourth-degree NURBS surface was developed. The method enables engineers to easily generate three-dimensional complex blade shapes that have inherently good aerodynamic performance and constraint satisfaction. The developed design method has three steps. First, 2D aerofoils are independently generated at each design height. The convergent or convergent-divergent aerofoils are selected on the basis of the outlet Mach number. The convergent flow path is defined by a fourth-degree NURBS curve to preserve the continuity of the slope of the curvature. The divergent flow path for supersonic flow is generated by the method of characteristic curves to avoid strong shock waves. The inlet and outlet angles are constrained to coincide with the flow angle of the velocity triangle. The design parameters, such as chord length, stagger angle and control points of NURBS are automatically decided using an evolutionary optimization technique NSGA-II to minimize the loss by computational fluid dynamics. Therefore, fewer man-hours are needed for design work and better proficiency is not a significant requirement. Second, the number of control points and knot vectors are equalized for all aerofoils by inserting or removing knots and fitting the divergent part by the fourth-degree NURBS curve. Finally, all aerofoils are stacked radially, for example, along the centroid axis, and the fourth-degree NURBS surface is generated by interpolating the control points of the NURBS curves of all the aerofoils. This design method can easily generate long blades of the last stage for steam turbines. The blade has a surface with continuity of the slope of curvature in all directions and good aerodynamic performance under constraints.

Ship Lines Modeling Theory of High-Speed Ship Based on the Partial Differential Equations

2012 ◽  
Vol 602-604 ◽  
pp. 1827-1830
Author(s):  
Chun Tao Li ◽  
Xiang Qi ◽  
Jian Shi ◽  
Zhong Kun Shi ◽  
Huan Qi
Keyword(s):  
Differential Geometry ◽  
High Speed ◽  
Three Dimensional ◽  
Automatic Generation ◽  
Surface Shape ◽  
Type Curves ◽  
Planar Curve ◽  
Starting Point ◽  
Curve Modeling ◽  
Modeling Theory

Based on the analysis of molded line geometrical characteristic and boundary conditions of high-speed frigate’s hull by using differential geometry, we report a curve modeling principle to express the hull line geometry through differential geometry application. The starting point of this molded-line automatic generation method is using the planar curve to express 3D surface shape. The first problem to be solved is how to get shape functions which describe every design ship curves via the the hull type curves geometry. The second problem to be solved is how the two-dimensional function, which describe ship lines, transformed to the hull shape function designed of three-dimensional hull surface, namely “mathematic ship”.

Methodology for Pipeline Route Selection Using the NSGA II and Distance Transform Algorithms

2011 ◽  
Author(s):  
Sigurjon N. Kjaernested ◽  
Magnus Th. Jonsson ◽  
Halldor Palsson
Keyword(s):  
Genetic Algorithm ◽  
Optimal Path ◽  
Initial Population ◽  
Distance Transform ◽  
Route Selection ◽  
Visual Effects ◽  
Nsga Ii ◽  
Shortest Route ◽  
Route Length ◽  
Pipeline Route

The objective of this study is to develop a methodology for use in geothermal pipeline route selection. Special emphasis is placed on finding the shortest route and minimizing the visual affects of the pipeline. Two different approaches are taken to solving the problem. In the first method a distance transform algorithm is used both for visual effects ranking and to obtain the optimal path. Subsequently a genetic algorithm is used to modify the route with regards to necessary expansion units. Included in the tool is site selection for separators and pipeline gathering points based on visual effects, incline, inaccessible areas and total distance to boreholes. The second method uses the Non-dominated sorting genetic algorithm II (NSGA II) to obtain the optimal path with regards visual effects, route length and pipeline gradient. This method uses the distance transform ranking method along with constraints on route length to generate the initial population for the genetic algorithm. The methods are implemented for the Hverahlið geothermal area.

Three-Dimensional Aerodynamic Optimization of a Multi-Stage Axial Compressor

2016 ◽  
Author(s):  
Tao Ning ◽  
Chun-wei Gu ◽  
Xiao-tang Li ◽  
Tai-qiu Liu
Keyword(s):  
Genetic Algorithm ◽  
Surrogate Model ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Optimization Method ◽  
Operating Point ◽  
Design Parameters ◽  
Aerodynamic Optimization ◽  
Stall Margin

An optimization method combined of a genetic algorithm, an artificial neural network, a CFD solver and a blade generator, is developed in this research and applied in the three-dimensional blading design of a newly designed highly-loaded 5-stage axial compressor. The adaptive probabilities of crossover and mutation, non-uniform mutation operator and elitism operator are employed to improve the convergence of the genetic algorithm. Considering both the optimization efficiency and effectiveness, a mixture of high-fidelity multistage CFD method and approximate surrogate model of the feed-forward ANN is used to evaluate the fitness. In particular, the database is updated dynamically and used to re-train the surrogate model of ANN for improving the accuracy for predicting. The last stator of the compressor is optimized at the near stall operating point. The tip bow with relative bow height Hb and bow angle αb are treated as design parameters. The adiabatic efficiency as well as the penalty of mass flow and total pressure ratio constitute the objective functions to be maximized. The optimum (Hb = 0.881, αb = 14.7°) obtains 0.4% adiabatic efficiency increase for the whole compressor at the optimized operating point. The detailed aerodynamic is compared between the baseline and optimized stator, and the mechanism is analyzed. The optimized version obtains 5.1% increase in stall margin and maintains the efficiency at the design point.

An Adaptive Changeability Approach of Flow Path Feature in Hydraulic Manifold Blocks Design

2011 ◽  
Vol 311-313 ◽  
pp. 787-791 ◽  
Author(s):  
Guang Li ◽  
Wen Tie Niu ◽  
Da Wei Zhang ◽  
Wei Guo Gao
Keyword(s):  
Genetic Algorithm ◽  
Hybrid Model ◽  
Adjacency Matrix ◽  
Traditional Method ◽  
Flow Path ◽  
Design Parameters ◽  
Adjacency Graph ◽  
Design Change ◽  
Body Model ◽  
Connection Design

The connection design of flow path is the most important task in Hydraulic Manifold Blocks (HMB) design. But the traditional method of feature design can not dynamically change the topology configuration and parameters of flow path when the design changed. This paper use a hybrid model consisting of temporary body model and B-Rep model, and represent flow path pattern using adjacency graph, adjacency matrix, weight matrix and degree array. The design parameters can be optimized by non-dominated sorting genetic algorithm (NSGA2). The topology configuration of flow path can adaptively change according to the design change.

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