scholarly journals Optimal Design of Multi-section Proportional Directional Valve Throttle Grooves with Artificial Neural Networks

2018 ◽  
Vol 237 ◽  
pp. 03003 ◽  
Author(s):  
Xiaolu Zhang ◽  
Anlin Wang ◽  
Jiangwei Tang
Keyword(s):  
Optimal Design ◽  
Design Method ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Flow Stability ◽  
Complex Flow ◽  
Physical Test ◽  
Flow Field Characteristics ◽  
Structure Boundary ◽  
Proportional Directional Valve

This paper presents a method for design multi-section proportional directional valve Throttle grooves with ANN method, which aims at getting a better flow stability. There exists a coupling matter during the opening and closing process between the throttling notches, so that it’s difficult to parameterize the complex flow field characteristics Cd and the structure boundary of the spool grooves. However, in this paper, an ANN was built with data from CFD results, while the typical structural parameters (U type, the O-type and C-type), operating parameters was input vectors, the discharge coefficient as output vectors. Meanwhile, all of the needed data is taken from the three-dimensional CFD analysis, which are organized properly and verified by a bench scale test on a rig. Then, with throttling stiffness as optimization objective to evaluate flow stability, an optimal design process is carried out to optimize to optimize the structure of coupling grooves with ANN models and genetic algorithm. Ultimately, the optimized structure is verified better by the physical test on test rig, therefore, the significance of design method is proved.

scholarly journals Coupled Fluid–Solid Numerical Simulation for Flow Field Characteristics and Supporting Performance of Flexible Support Cylindrical Gas Film Seal

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Junfeng Sun ◽  
Meihong Liu ◽  
Zhen Xu ◽  
Taohong Liao ◽  
Xiangping Hu ◽  
...  
Keyword(s):  
Flow Field ◽  
Film Thickness ◽  
Fluid Dynamic ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
High Rotational Speed ◽  
Flexible Support ◽  
Flow Field Characteristics

A new type of cylindrical gas film seal (CGFS) with a flexible support is proposed according to the working characteristics of the fluid dynamic seal in high-rotational-speed fluid machinery, such as aero-engines and centrifuges. Compared with the CGFS without a flexible support, the CGFS with flexible support presents stronger radial floating characteristics since it absorbs vibration and reduces thermal deformation of the rotor system. Combined with the structural characteristics of a film seal, an analytical model of CGFS with a flexible wave foil is established. Based on the fluid-structure coupling analysis method, the three-dimensional flow field of a straight-groove CGFS model is simulated to study the effects of operating and structural parameters on the steady-state characteristics and the effects of gas film thickness, eccentricity, and the number of wave foils on the equivalent stress of the flexible support. Simulation results show that the film stiffness increases significantly when the depth of groove increases. When the gas film thickness increases, the average equivalent stress of the flexible support first decreases and then stabilizes. Furthermore, the number of wave foils affects the average foils thickness. Therefore, when selecting the number of wave foils, the support stiffness and buffer capacity should be considered simultaneously.

Modeling and Optimization of Ultra High Pressure Vessel With Self-Protective Flat Steel Ribbons Wound and Tooth-Locked Quick-Actuating End Closure

2008 ◽  
Author(s):  
Xin Ma ◽  
Zhongpei Ning ◽  
Honggang Chen ◽  
Jinyang Zheng
Keyword(s):  
High Pressure ◽  
Fatigue Life ◽  
Pressure Vessel ◽  
Design Method ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Peak Stress ◽  
High Pressure Vessel ◽  
Ultra High Pressure ◽  
Flat Steel

Ultra-High Pressure Vessel (UHPV) with self-protective Flat Steel Ribbons (FSR) wound and Tooth-Locked Quick-Actuating (TLQA) end closure is a new type of vessel developed in recent years. When the structural parameters of its TLQA and Buttress Thread (BT) end closure are determined using the ordinary engineering design method, Design by Analysis (DBA) shows that the requirement on fatigue life of this unique UHPV could hardly be satisfied. To solve the above problem, an integrated FE modeling method has been proposed in this paper. To investigate the fatigue life of TLQA and BT end closures of a full-scale unique UHPV, a three-dimensional (3-D) Finite Element (FE) solid model and a two-dimensional (2-D) FE axisymmetric model are built in FE software ANSYS, respectively., Nonlinear FE analysis and orthogonal testing are both conducted to obtain the optimum structure strength, in which the peak stress in the TLQA or BT end closure of the unique UHPV is taken as an optimal target. The important parameters, such as root structure of teeth, contact pressure between the pre-stressed collar and the cylinder end, the knuckle radius, the buttress thread profile and the local structure of the cylinder, are optimized. As a result, both the stress distribution at the root of teeth and the axial load carried by each thread are improved. Therefore, the load-carrying capacity of the end closure has been reinforced and the fatigue life of unique UHPV has been extended.

scholarly journals Modal characteristics of harmonic gear transmission flexspline based on orthogonal design method

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 819-827
Author(s):  
Leyu Wei ◽  
Jie Yang ◽  
Changlu Wang ◽  
Xingxing Wang ◽  
Xinmeng Liu
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Natural Frequencies ◽  
Design Method ◽  
Orthogonal Design ◽  
Structural Parameters ◽  
Gear Transmission ◽  
Modal Characteristics ◽  
Orthogonal Design Method ◽  
The Stability

Abstract The flexspline features several modal characteristics that are related to its structural parameters, which could impose an impact on the stability and reliability of the system of harmonic gear transmission. In this article, we have integrated the method of orthogonal design with the approach of finite element, so as to study the modal characteristics of flexspline under varying structural parameters. Furthermore, we have analyzed the ways of how varying structural parameters could impose an impact on the first eight-order natural frequencies of flexspline. In addition, by adopting the method of range and variance analysis for the obtained data, we have examined the influence imposed by varying structural parameters on the modal characteristics of flexspline, which could lay a foundation for the optimal design of the structural parameters of flexspline.

Performance analysis and optimal design of fast tool servo used for machining microstructured surfaces

2008 ◽  
Vol 222 (8) ◽  
pp. 1541-1546 ◽  
Author(s):  
Y Yang ◽  
S Chen ◽  
D Huo ◽  
K Cheng
Keyword(s):  
Optimal Design ◽  
Design Method ◽  
Structural Parameters ◽  
Fast Tool Servo ◽  
Element Analysis ◽  
Microstructured Surfaces ◽  
The Finite Element Analysis ◽  
Machining System ◽  
Positioning Device ◽  
Ultra Precision

Ultra-precision machining with a fast tool servo (FTS) is one of the leading methodologies for the fabrication of microstructured surfaces. FTS is an independently operated positioning device that plays an important role in the machining system. The complexity of surface features and the surface quality depend largely on the behaviour of FTS. In this paper, according to the analysis of required performance, a novel FTS is developed with structural parameters optimized by the finite-element analysis (FEA) method. Finally, a series of tests are carried out to evaluate the performance of the FTS and validate the value obtained by the FEA software. The results show that the FTS has a travel of 20 μm, a positioning resolution of 5 nm, a static stiffness of 33.62 N/μm, and a dominant natural frequency of 2191 Hz and demonstrate the validity of the optimal design method.

Frequency Optimal Design Method and Application

2011 ◽  
Vol 201-203 ◽  
pp. 1279-1283
Author(s):  
Shou Yi Bi ◽  
Xing Pei Liang
Keyword(s):  
Optimal Design ◽  
Design Method ◽  
Mathematical Problem ◽  
Three Dimensional ◽  
Mathematical Optimization ◽  
Element Model ◽  
Optimization Method ◽  
Finite Model ◽  
Design Variables ◽  
Analysis System

A program for frequency optimal design of structure composed of bar, beam, plate is developed based on finite analysis system ZR[1] that finite element model, including mesh generation of truss element, beam element and plate element, is automatically generated. Because of integrated with three dimensional CAD, specification of boundary conditions and design variables can be finished based on the three dimensional CAD model, so user need not deal with nodal and element of finite model in the procedure of forming finite model and specifying mathematical problem for optimization. This paper introduces a new method how to insert the frequency sensitivity analysis process into the structural analysis program, integrate mathematical optimization method and design structure based frequency optimization. The program is applied to the optimal design of actual engineering. The results are acceptable.

Development of the design method for the optimal design of the Neutron Converter experimental plant

2020 ◽  
Author(s):  
Timur Smetani ◽  
Elizaveta Gureva ◽  
Vyacheslav Andreev ◽  
Natalya Tarasova ◽  
Nikolai Andree
Keyword(s):  
Optimal Design ◽  
Flux Density ◽  
Design Process ◽  
Design Method ◽  
Fast Neutrons ◽  
Experimental Plant ◽  
Plant Design ◽  
State Technical ◽  
Research Organizations ◽  
Neutron Converter

The article discusses methods for optimizing the design of the Neutron Converter research plant design with parameters that are most suitable for a particular consumer. 38 similar plant structures with different materials and sources were calculated, on the basis of which the most optimal options were found. As part of the interaction between OKBM Afrikantov JSC and the Nizhny Novgorod State Technical University named after R. E. Alekseev, the Neutron Converter research plant was designed and assembled. The universal neutron converter is a device for converting a stream of fast neutrons emitted by isotopic sources into a "standardized" value of flux density with known parameters in the volume of the central part of the product, which is the working part of the universal neutron converter. To supply neutron converters to other customer organizations (universities, research organizations and collective centers), it is necessary to take into account the experience of operating an existing facility, as well as rationalize the design process of each specific instance in accordance with the requirements of the customer.

scholarly journals Brain capillary structures of schizophrenia cases and controls show a correlation with their neuron structures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rino Saiga ◽  
Masayuki Uesugi ◽  
Akihisa Takeuchi ◽  
Kentaro Uesugi ◽  
Yoshio Suzuki ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Superior Temporal Gyrus ◽  
Anterior Cingulate ◽  
Dimensional Structure ◽  
Constant Diameter ◽  
The Mean ◽  
Cartesian Coordinate ◽  
Micrometer Scale

AbstractBrain blood vessels constitute a micrometer-scale vascular network responsible for supply of oxygen and nutrition. In this study, we analyzed cerebral tissues of the anterior cingulate cortex and superior temporal gyrus of schizophrenia cases and age/gender-matched controls by using synchrotron radiation microtomography or micro-CT in order to examine the three-dimensional structure of cerebral vessels. Over 1 m of cerebral blood vessels was traced to build Cartesian-coordinate models, which were then used for calculating structural parameters including the diameter and curvature of the vessels. The distribution of vessel outer diameters showed a peak at 7–9 μm, corresponding to the diameter of the capillaries. Mean curvatures of the capillary vessels showed a significant correlation to the mean curvatures of neurites, while the mean capillary diameter was almost constant, independent of the cases. Our previous studies indicated that the neurites of schizophrenia cases are thin and tortuous compared to controls. The curved capillaries with a constant diameter should occupy a nearly constant volume, while neurons suffering from neurite thinning should have reduced volumes, resulting in a volumetric imbalance between the neurons and the vessels. We suggest that the observed structural correlation between neurons and blood vessels is related to neurovascular abnormalities in schizophrenia.

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