Two-Phase Flow Correlations in Air/Oil Systems of Aero Engines

1991 ◽  
Author(s):  
H. Zimmermann ◽  
A. Kammerer ◽  
R. Fischer ◽  
D. Rebhan
Keyword(s):  
Two Phase Flow ◽  
Phase Flow ◽  
Test Results ◽  
Centrifugal Forces ◽  
Flow Conditions ◽  
Two Phase ◽  
Oil Mixtures ◽  
Water Test ◽  
Flow Effects ◽  
Aero Engines

A strategy is outlined on how to introduce two-phase flow correlations into air/oil system calculations for aero engines. The importance of two-phase flow effects is highlighted by demonstrating their particular significance for the high altitude performance of a vent system. For air/oil mixtures very little can be obtained from the literature and correlations derived from air/water test results have to be corrected. For critical flow conditions in restrictors an improved method is developed. Some test data obtained for air/oil mixtures show, that the proposed correlations agree fairly well. Furthermore, it is shown how numerical methods for this complex field of fluid dynamics can be used in the future by the example of phase demixing by centrifugal forces.

scholarly journals Simulation of the Secondary Air System of Aero Engines

1994 ◽  
Vol 116 (2) ◽  
pp. 306-315 ◽  
Author(s):  
K. J. Kutz ◽  
T. M. Speer
Keyword(s):  
Computer Program ◽  
Nonlinear Equations ◽  
Two Phase Flow ◽  
Flow System ◽  
Phase Flow ◽  
Test Results ◽  
Two Phase ◽  
Engine Operation ◽  
Secondary Air ◽  
Aero Engines

This paper describes a computer program for the simulation of secondary air systems. Typical flow system elements are presented, such as restrictors, tappings, seals, vortices, and coverplates. Two-phase flow as occurring in bearing chamber vent systems is briefly discussed. An algorithm is described for the solution of the resulting nonlinear equations. The validity of the simulation over the engine operation envelope is demonstrated by a comparison with test results.

Numerical Simulation of Gas-Liquid Two-Phase Flow in Multi-Impeller Pre-Oxidation Reactor

2013 ◽  
Vol 331 ◽  
pp. 205-210
Author(s):  
Mao He Lai ◽  
Dong Chen ◽  
Deng Feng Han ◽  
Qiang Li
Keyword(s):  
Numerical Simulation ◽  
Cross Sections ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Test Results ◽  
Two Phase ◽  
Water Test ◽  
Simulation Results ◽  
Oxidation Reactor ◽  
Optimum Design Parameter

Numerical simulation of gas-liquid two-phase flow in the tank of multi-impeller pre-oxidation reactor was studied in this article. The dispersion of gas phase in liquid phase without agitator mixing and the distribution of gas-liquid two-phase flow with agitator mixing were simulated. The characteristics of gas-liquid two-phase flow and the regularities of the gas distribution in the reactor were achieved through analyzing the numerical simulation results. The dissolved oxygen in different cross sections of the reactor without agitator mixing was measured in the water test, which was used to verify the numerical simulation results. And the test results were almost the same with the simulation results, which can provide a reference for determining the optimum design parameter of this type of reactor.

scholarly journals Simulation of the Secondary Air System of Aero Engines

1992 ◽  
Author(s):  
K. J. Kutz ◽  
T. M. Speer
Keyword(s):  
Computer Program ◽  
Nonlinear Equations ◽  
Two Phase Flow ◽  
Flow System ◽  
Phase Flow ◽  
Test Results ◽  
Two Phase ◽  
Engine Operation ◽  
Secondary Air ◽  
Aero Engines

This paper describes a computer program for the simulation of secondary air systems. Typical flow system elements are presented, such as restrictors, tappings, seals, vortices, and coverplates. Two-phase flow as occuring in bearing chamber vent systems is briefly discussed. The algorithm is described for the solution of the resulting nonlinear equations. The validity of the simulation over the engine operation envelope is demonstrated by a comparison with test results.

On the performance of a cascade of turbine rotor tip section blading in wet steam Part 3: Wake traverses

1997 ◽  
Vol 211 (8) ◽  
pp. 639-648 ◽  
Author(s):  
F Bakhtar ◽  
H Mashmoushy ◽  
O C Jadayel
Keyword(s):  
Liquid Phase ◽  
Two Phase Flow ◽  
Turbine Rotor ◽  
Phase Flow ◽  
Wet Steam ◽  
Flow Conditions ◽  
Two Phase ◽  
Blow Down ◽  
The Third ◽  
Phase Mixture

During the course of expansion of steam in turbines the fluid first supercools and then nucleates to become a two-phase mixture. The liquid phase consists of a large number of extremely small droplets which are difficult to generate except by nucleation. To reproduce turbine two-phase flow conditions requires a supply of supercooled vapour which can be achieved under blow-down conditions by the equipment employed. This paper is the third of a set describing an investigation into the performance of a cascade of rotor tip section profiles in wet steam and presents the results of the wake traverses.

Prediction of Pump Performance Under Air-Water Two-Phase Flow Based on a Bubbly Flow Model

1993 ◽  
Vol 115 (4) ◽  
pp. 781-783 ◽  
Author(s):  
Kiyoshi Minemura ◽  
Tomomi Uchiyama
Keyword(s):  
Two Phase Flow ◽  
Bubbly Flow ◽  
Phase Flow ◽  
Centrifugal Pumps ◽  
Flow Conditions ◽  
Two Phase ◽  
Performance Change ◽  
Void Fractions ◽  
Two Phases

This paper is concerned with the determination of the performance change in centrifugal pumps operating under two-phase flow conditions using the velocities and void fractions calculated under the assumption of an inviscid bubbly flow with slippage between the two phases. The estimated changes in the theoretical head are confirmed with experiments within the range of bubbly flow regime.

Local characteristic of horizontal air–water two-phase flow by wire-mesh sensor

2016 ◽  
Vol 40 (3) ◽  
pp. 746-761 ◽  
Author(s):  
Weiling Liu ◽  
Chao Tan ◽  
Feng Dong
Keyword(s):  
Void Fraction ◽  
Transient Flow ◽  
Two Phase Flow ◽  
Wire Mesh ◽  
Local Characteristic ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Local Flow

Two-phase flow widely exists in many industries. Understanding local characteristics of two-phase flow under different flow conditions in piping systems is important to design and optimize the industrial process for higher productivity and lower cost. Air–water two-phase flow experiments were conducted with a 16×16 conductivity wire-mesh sensor (WMS) in a horizontal pipe of a multiphase flow facility. The cross-sectional void fraction time series was analysed by the probability density function (PDF), which described the void fraction fluctuation at different flow conditions. The changes and causes of PDFs during a flow regime transition were analysed. The local structure and flow behaviour were characterized by the local flow spectrum energy analysis and the local void fraction distribution (horizontal, vertical and radial direction) analysis. Finally, three-dimensional transient flow fluctuation energy evolution and characteristic scale distribution based on wavelet analysis of air–water two-phase flow were presented, which revealed the structural features of each phase in two-phase flow.

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