Performance Improvement of Sewer Trenchless Entire Repair Method by Using the Multifunctional Safety High-Pressure Hose

2016 ◽  
Vol 20 ◽  
pp. 7-13
Author(s):  
Jang-Hwan Choi ◽  
◽  
Bong-Su Lim ◽  
Won-Yong Lee
Keyword(s):  
High Pressure ◽  
Performance Improvement ◽  
Repair Method

scholarly journals Investigation on the Optimal Design and Flow Mechanism of High Pressure Ratio Impeller with Machine Learning Method

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Weilin Yi ◽  
Hongliang Cheng
Keyword(s):  
Machine Learning ◽  
High Pressure ◽  
Flow Field ◽  
Performance Improvement ◽  
Pressure Ratio ◽  
Leading Edge ◽  
Design Parameters ◽  
Support Vector ◽  
Peak Efficiency ◽  
High Pressure Ratio

The optimization of high-pressure ratio impeller with splitter blades is difficult because of large-scale design parameters, high time cost, and complex flow field. So few relative works are published. In this paper, an engineering-applied centrifugal impeller with ultrahigh pressure ratio 9 was selected as datum geometry. One kind of advanced optimization strategy including the parameterization of impeller with 41 parameters, high-quality CFD simulation, deep machine learning model based on SVR (Support Vector Machine), random forest, and multipoint genetic algorithm (MPGA) were set up based on the combination of commercial software and in-house python code. The optimization objective is to maximize the peak efficiency with the constraints of pressure-ratio at near stall point and choked mass flow. Results show that the peak efficiency increases by 1.24% and the overall performance is improved simultaneously. By comparing the details of the flow field, it is found that the weakening of the strength of shock wave, reduction of tip leakage flow rate near the leading edge, separation region near the root of leading edge, and more homogenous outlet flow distributions are the main reasons for performance improvement. It verified the reliability of the SVR-MPGA model for multiparameter optimization of high aerodynamic loading impeller and revealed the probable performance improvement pattern.

The Flow Analysis and Performance Improvement of the Flow Return System in High Pressure Fans

2012 ◽  
Vol 29 (4) ◽  
Author(s):  
Hung-Cheng Yen ◽  
Yung Jen Cheng ◽  
Jeng-Min Huang ◽  
Chi-Wen Lu ◽  
Yeah-Hann Tsai
Keyword(s):  
High Pressure ◽  
Performance Improvement ◽  
Flow Analysis ◽  
And Performance

scholarly journals Performance Improvement of Ship Propulsion Equipment Drien by High-Pressure Gas.

1995 ◽  
Vol 61 (583) ◽  
pp. 1029-1034
Author(s):  
Michihisa Tsutahara ◽  
Masahiko Sakamoto ◽  
Takeyoshi Kimura
Keyword(s):  
High Pressure ◽  
Performance Improvement ◽  
Ship Propulsion

scholarly journals Nonlinear dynamics of a bladed dual-shaft

2011 ◽  
pp. 207-225
Author(s):  
Marion Gruin ◽  
Fabrice Thouverez ◽  
Laurent Blanc ◽  
Pierrick Jean
Keyword(s):  
Nonlinear Dynamics ◽  
High Pressure ◽  
Performance Improvement ◽  
Dynamic Behaviour ◽  
Rotating Machinery ◽  
Experimental Results ◽  
Aircraft Engines ◽  
Bladed Disk ◽  
Nonlinear Features ◽  
Industrial Context

In the industrial context of performance improvement of dual-shaft aircraft engines, experimental results demonstrate how important it is to consider the influence of the dynamics of the high pressure (HP) shaft on the response of the bladed disk located on the low pressure (LP) shaft. Indeed, this coupling seems to play an important role in the design purposes in rotating machinery industry as it can have a significant impact on the dynamic behaviour of turbomachines. The model developed here consists of a HP shaft and a LP bladed shaft connected by an intershaft bearing. Nonlinear features of this intershaft bearing require the development of specific nonlinear algorithms. Thus, this paper aims at coupling the two modelling levels in order to grasp the nonlinear vibratory phenomena of a bladed dual-shaft under unbalances.

CREATE: Advanced CFD for HPC Performance Improvement

2012 ◽  
Author(s):  
A. Pesteil ◽  
D. Cellier ◽  
O. Domercq ◽  
V. Perrot ◽  
J. C. Boniface
Keyword(s):  
High Pressure ◽  
Performance Improvement ◽  
Optimization Methods ◽  
Computational Effort ◽  
Flow Path ◽  
Main Flow ◽  
Secondary Flows ◽  
Vortex Generators ◽  
Flow Vortex ◽  
Selection Of

The present paper provides an overview of technological evolutions aimed at improving the aerodynamic performance of Snecma’s High Pressure Compressors. Several concepts were investigated under its CREATE compressor research program, involving an extensive simulation effort. An overview of the computational approaches involved in the evaluation and selection of innovative and most promising concepts will be given in the paper. The main topics dealt with are: 1) Aeromechanical optimization of airfoils and flow path: In recent years, great efforts have been made to improve the aerodynamic design of airfoils. Among them, optimization methods have been progressively implemented in the design process with an increased complexity logic. The latest methods used at Snecma involve multi-objective, multi-parameters aeromechanical optimization including mean camber line, stacking axis, flow path contouring and more. This work is illustrated by two practical examples. 2) Vortex generators: In order to control the flow, vortex generators can be forecasted as a promising step forward. The goal is to create exogenous vorticity that will counter-balance the endogenous vorticity. Thus they appear as a tool to reduce losses and improve stability in highly loaded turbomachinery devices such as modern high pressure compressors. This section of the paper will give an overview of the dedicated numerical simulations completed. 3) Clocking: Numerous studies are related to the benefit drawn from turbine clocking on turbomachinery performance. However, fewer examples of successful compressor clocking exist. The recent capability of computational fluid dynamics tools to reduce the computational effort necessary to investigate such an issue (by the use of harmonic balance methodology) gives the opportunity for a renewed evaluation. 4) Optimization of shroud leakage flow with main flow: A strong interaction exists with the secondary flows originated in the inner flow path cavities. Coupled main flow path and cavities aerodynamic simulations were conducted to improve the relevance of the computations and understand the mechanisms involved. 5) Tandem bladings and splitters in axial rotors: The last aspect of the study was focused on dual blading concepts. After a brief review of the literature, some simulations were carried out to explore the relevance of such concepts from the viewpoint of modern high pressure compressors performance improvement.

Rotor Casing Contouring in High Pressure Stages of Heavy Duty Gas Turbine Compressors With Large Tip Clearance Heights

2009 ◽  
Author(s):  
Georg Kro¨ger ◽  
Christian Cornelius ◽  
Eberhard Nicke
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Performance Improvement ◽  
Axial Compressor ◽  
Tip Clearance ◽  
Pressure Stage ◽  
Design Point ◽  
Pressure Loss Coefficient ◽  
Exit Pressure ◽  
High Pressure Stage

Clearance leakage losses of axial compressor rotors and stators have a major impact on the overall compressor performance. The clearance heights in the last stages (high pressure stages) of a gas turbine compressor are very large in comparison to the low pressure stages due to mechanical constraints and small blade heights. The reduction of clearance leakage losses in a high pressure stage still holds an important potential for the overall performance improvement at design point conditions. In the following work, a method for tip clearance loss reduction by circumferential casing contouring above a high pressure stage rotor with a constant clearance height is presented. The subsonic compressor blade provides Siemens HPA-Family [1, 2, 3] airfoils. Starting over with a 3D-Optimization of the mentioned rotor casing the work additionally refers to the aerodynamic effects and the off design performance of the optimized geometry. It has been found that an optimized casing and blade tip contour lead to a smaller overall clearance mass flow and lower pressure loss coefficient of the clearance flow so that the endwall blockage is reduced and the stage performance is improved by about 0.35% at design point conditions. Furthermore it was found that the performance improvement drops with increasing exit pressure to about 0.1% close to stall conditions. At lower exit pressure values the optimized geometry provides an additional performance improvement in comparison to the baseline configuration.

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