Numerical Simulation of Aero-Engine Lubrication System

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Yaguo Lu ◽  
Zhenxia Liu ◽  
Shengqin Huang ◽  
Tao Xu
Keyword(s):  
Network Theory ◽  
Flow Resistance ◽  
Measured Data ◽  
Lubrication System ◽  
Computational Results ◽  
Analysis Software ◽  
Aero Engine ◽  
Oil Flow ◽  
Flow Pressure

A software, general analysis software of aero-engine lubrication system (GASLS), for simulating aero-engine lubrication system is presented. The software is capable of analyzing the flow, pressure, and temperature distribution in the lubrication system. The network theory and mathematical model of flow resistance for elements that include pipes, elbows, thick orifice, reductions, expansions, and nozzles are presented first. Second, the special element and combined element are introduced for treating the bearing chamber, heat exchanger, and gearbox and simplifying the calculation network, respectively. Lastly, a case study for an aero-engine lubrication system is illustrated. The distribution of oil flow, pressure, and temperature is calculated, and the oil flow results in different branches of lubrication system are compared with the experimental data. The comparison indicts that computational results agree well with the measured data. The software may be helpful in designing and analyzing aero-engine lubrication system.

Multi-Factor Coupling Analysis of Altitude Performance of Lubrication System in Helicopter

2010 ◽  
Author(s):  
Ming Li ◽  
Hongxia Gao ◽  
Jianzu Yu ◽  
Yi Zhou ◽  
Xuemin Niu
Keyword(s):  
Performance Prediction ◽  
Calculation Method ◽  
Flow Resistance ◽  
Integrated Design ◽  
Lubricating Oil ◽  
Lubrication System ◽  
Analysis Software ◽  
Practical Tool ◽  
Coupling Calculation ◽  
Good Agreement

Good altitude performance of lubrication system ensures flying performance of the helicopter. Both engine and reducer need lubricating oil to cool themselves, to keep stable and decrease malfunction in flying tasks. In this article, a multi-factor coupling calculation method is put forward for altitude performance analysis of lubrication system in “Zhi X” main reducer system, taking into consideration of heat transfer and flow resistance characteristics of every component, off-design performance of the fan and dynamic characteristic of heat exchanger. Performance parameters of each component are calculated, such as temperature, pressure and flux. The results are in good agreement with numerical results of FM2. Then an analysis software for altitude performance of lubrication system is developed for “Zhi X” based on the multi-factor coupling calculation method, which is regarded as a scientific and practical tool for altitude performance prediction and integrated design of lubrication system in helicopter.

Numerical DPM Model for Two-Phase Flow in Aero-Engine Bearing Chamber

2011 ◽  
Vol 201-203 ◽  
pp. 2267-2270 ◽  
Author(s):  
Rang Shu Xu ◽  
Juan Juan Wang ◽  
Wei Xu ◽  
Li Bo Liu
Keyword(s):  
Two Phase Flow ◽  
Lubricating Oil ◽  
Phase Flow ◽  
Lubrication System ◽  
Discrete Phase Model ◽  
Main Bearing ◽  
Two Phase ◽  
Aero Engine ◽  
Oil Flow ◽  
Discrete Phase

The main bearing chamber is a major part of the lubrication system in aero-engine, it is important to know the influence of operation parameters on air/oil two-phase flow, so as to optimize the design of aero-engine lubrication system. The air/oil two-phase flow in a simplified bearing chamber model in an aero-engine is simulated by means of discrete phase model (DPM) and wall-film model with CFD approach. The simulation results coincide with the existing experimental data. The oil film thickness and concentration of droplets in bearing chamber are presented at different rotational speeds and different lubricating oil flow rates.

scholarly journals Exploring Factors Influencing Scenarios Evolution of Waste NIMBY Crisis: Analysis of Typical Cases in China

2021 ◽  
Vol 18 (4) ◽  
pp. 2006
Author(s):  
Ling He ◽  
Qing Yang ◽  
Xingxing Liu ◽  
Lingmei Fu ◽  
Jinmei Wang
Keyword(s):  
Network Theory ◽  
Development Process ◽  
Dynamic Bayesian Network ◽  
Impact Factors ◽  
Social Stability ◽  
Ground Theory ◽  
Evolution Path ◽  
Dynamic Scenario ◽  
The Impact

As the impact factors of the waste Not-In-My-Back Yard (NIMBY) crisis are complex, and the scenario evolution path of it is diverse. Once the crisis is not handled properly, it will bring adverse effects on the construction of waste NIMBY facilities, economic development and social stability. Consequently, based on ground theory, this paper takes the waste NIMBY crisis in China from 2006 to 2019 as typical cases, through coding analysis, scenario evolution factors of waste NIMBY crisis are established. Furtherly, three key scenarios were obtained, namely, external situation (E), situation state (S), emergency management (M), what is more, scenario evolution law of waste NIMBY crisis is revealed. Then, the dynamic Bayesian network theory is used to construct the dynamic scenario evolution network of waste NIMBY crisis. Finally, based on the above models, Xiantao waste NIMBY crisis is taken as a case study, and the dynamic process of scenario evolution network is visually displayed by using Netica. The simulation results show that the scenario evolution network of Xiantao waste NIMBY crisis is basically consistent with the actual incident development process, which confirms the effectiveness and feasibility of the model.

Institutionalized Education: Journalism and Mass Communication Education in Pakistan

2021 ◽  
pp. 1326365X2110096
Author(s):  
David Bockino ◽  
Amir Ilyas
Keyword(s):  
Network Theory ◽  
Mass Communication ◽  
Qualitative Method ◽  
Actor Network Theory ◽  
Power Structures ◽  
Communication Education ◽  
Organizational Field ◽  
The World ◽  
Mass Communication Education

This article uses an examination of journalism and mass communication (JMC) education in Pakistan as a case study to explore the consequences of increased homogenization of JMC education around the world. Anchored by a qualitative method that relies heavily on actor-network theory, the study identifies key moments and people in the trajectory of five Pakistani programmes and explores the connection between these programmes and the larger JMC organizational field. The study concludes by questioning the efficacy of the current power structures within the supranational JMC organizational field before discussing how these influences could potentially be mitigated moving forward.

scholarly journals Inverse Problem for Looped River Networks – Lower oder River Case Study

2013 ◽  
Vol 39 (1) ◽  
pp. 105-118
Author(s):  
Jacek Kurnatowski
Keyword(s):  
Mathematical Modeling ◽  
Flow Resistance ◽  
Flow Distribution ◽  
River Networks ◽  
Sensitivity Equation ◽  
Flow Measurements ◽  
Sensitivity Equation Method ◽  
Coefficients Identification ◽  
Oder River

Abstract Identification of coefficients determining flow resistance, in particular Manning’s roughness coefficients, is one of the possible inverse problems of mathematical modeling of flow distribution in looped river networks. The paper presents the solution of this problem for the lower Oder River network consisting of 78 branches connected by 62 nodes. Using results of six sets of flow measurements at particular network branches it was demonstrated that the application of iterative algorithm for roughness coefficients identification on the basis of the sensitivity-equation method leads to the explicit solution for all network branches, independent from initial values of identified coefficients.

Investigation of Heat Transfer for Shell-Tube Fuel-Cooled Heat Exchanger

2013 ◽  
Vol 378 ◽  
pp. 459-465
Author(s):  
Ya Guo Lu ◽  
Peng Fei Zhu
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Relative Error ◽  
Absolute Error ◽  
Heat Transfer Characteristics ◽  
Shell Side ◽  
Transfer Characteristics ◽  
Aero Engine ◽  
The Absolute

A calculate method based on ε-NTU model for heat transfer characteristics of shell-tube fuel-cooled heat exchanger of aero-engine lubrication system was built. The heat convection coefficient was obtained by a dimensionless curve (Re~StPr2/3), which was detailed introduced as well. A case study was executed at last. The absolute error of the outlet lubrication of the tube side and the shell side between the value of calculation and experiment was less than ±10°C, and the relative error was less than 6.5%. The absolute error of the heat transferred between calculation and experiment was less than ±0.9kW, and the relative error was less than 7.4%. It indicates that the mothod is available for the investigation of heat transfer characteristics of shell-tube fuel-cooled heat exchanger.

Regression Analysis on Influences of Hem Parameters on Flare Sagging of Semi-Circular Skirt

2011 ◽  
Vol 331 ◽  
pp. 594-598
Author(s):  
Hong Ni
Keyword(s):  
Regression Analysis ◽  
Statistical Analysis ◽  
Measured Data ◽  
Silk Fabric ◽  
Linear Regression Equation ◽  
Analysis Software ◽  
Wool Fabrics ◽  
Object Of Study ◽  
The Relationship ◽  
Statistical Analysis Software

Select 45 pieces of silk, cotton and wool fabrics in total, with semi-circular skirt modeling as object of study, investigate the relationship between flare sagging in straight & inclined grains of skirt pieces and fabric types, analyze the influence of hem parameters on flare sagging of semi-circular skirt and obtain multiple linear regression equation by disposing the measured data with SPSS statistical analysis software. The study result shows that the skirt hem of silk fabric is sagging more significantly than that of cotton and wool fabrics and there is a multi-linear relationship between semi-circular flare sagging and parameters.The research of this subject has both theoretical value and practical value.

Mobilizing a fast policy fix: Exploring the translation of 10-year plans to end homelessness in Alberta, Canada

2019 ◽  
Vol 38 (3) ◽  
pp. 503-521
Author(s):  
Joshua Evans ◽  
Jeffrey R Masuda
Keyword(s):  
Federal Government ◽  
Network Theory ◽  
Actor Network Theory ◽  
Housing First ◽  
Adaptive Governance ◽  
Technical Expertise ◽  
Dense Network ◽  
The U.S ◽  
Over Time

The management of homelessness has taken various forms over time. In 2003, the U.S. federal government significantly shifted its approach, ambitiously committing to end homelessness within 10 years by targeting the chronically homeless using the Housing First model. This approach to homelessness has rapidly spread across North America and beyond. This article is concerned with how the mobility of these 10-year plans has been realized. Drawing on Peck and Theodore’s concept of “fast policy,” and borrowing perspectives developed in actor-network theory, the article develops a case study of Alberta, Canada, to chronicle how 10-year plans were translated through a dense network of political alignments, socio-technical expertise, and statistical inscriptions. A close examination of these translations invites us to problematize this socio-technical infrastructure as a powerful mode of adaptive governance closely associated with the dynamism of neoliberalism itself.

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