The numerical analysis of the unsteady flow in the three - dimensional multiphase mixing flow field

Unsteady flow of a single six-blade ruston turbine in stirred tank is numerically simulated by using the large eddy simulation. Then the effect of the turbine installation position on mixing flow field is studied. The result shows that with a relatively low paddle installation position, mixing effect at the bottom of tank is obvious, while which go against the materials at the top layer mixing. When the paddle is installed at the top of the stirred tank, liquid splash and a concave downward liquid surface are easily caused. Finally the cavitation phenomenon is generated. When the paddle is installed from 1/3H to 2/3H, there are a uniform flow field distribution and higher average velocity flow. Large size vortex structures at the top and the bottom of the paddle are obvious which is beneficial to mix the materials.

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Three-Dimensional Numerical Analysis of LOX/Kerosene Engine Exhaust Plume Flow Field Characteristics

International Journal of Aerospace Engineering ◽

10.1155/2017/4768376 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Hong-hua Cai ◽

Wan-sheng Nie ◽

Xin-lei Yang ◽

Rui Wu ◽

Ling-yu Su

Keyword(s):

Numerical Analysis ◽

Flow Field ◽

Chemical Reaction ◽

Reaction Mechanisms ◽

Three Dimensional ◽

Engine Exhaust ◽

Exhaust Plume ◽

Flow Field Characteristics ◽

Chemical Reaction Mechanisms ◽

Plume Flow

Aiming at calculating and studying the flow field characteristics of engine exhaust plume and comparative analyzing the effects of different chemical reaction mechanisms on the engine exhaust plume flow field characteristics, a method considering fully the combustion state influence is put forward, which is applied to exhaust plume flow field calculation of multinozzle engine. On this basis, a three-dimensional numerical analysis of the effects of different chemical reaction mechanisms on LOX/kerosene engine exhaust plume flow field characteristics was carried out. It is found that multistep chemical reaction can accurately describe the combustion process in the LOX/kerosene engine, the average chamber pressure from the calculation is 4.63% greater than that of the test, and the average chamber temperature from the calculation is 3.34% greater than that from the thermodynamic calculation. The exhaust plumes of single nozzle and double nozzle calculated using the global chemical reaction are longer than those using the multistep chemical reaction; the highest temperature and the highest velocity on the plume axis calculated using the former are greater than that using the latter. The important influence of chemical reaction mechanism must be considered in the study of the fixing structure of double nozzle engine on the rocket body.

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Time Accurate Euler Simulation of Interaction of Nozzle Wake and Secondary Flow With Rotor Blade in an Axial Turbine Stage Using Nonreflecting Boundary Conditions

Volume 1: Turbomachinery ◽

10.1115/95-gt-230 ◽

1995 ◽

Author(s):

S. Fan ◽

B. Lakshminarayana

Keyword(s):

Flow Field ◽

Boundary Conditions ◽

Unsteady Flow ◽

Secondary Flow ◽

Rotor Blade ◽

Three Dimensional ◽

Computational Domain ◽

Turbine Stage ◽

Axial Turbine ◽

Unsteady Pressure

The objective of this paper is to investigate the three dimensional unsteady flow interactions in a turbomachine stage. A three-dimensional time accurate Euler code has been developed using an explicit four-stage Runge-Kutta scheme. Three-dimensional unsteady non-reflecting boundary conditions are formulated at the inlet and at the outlet of the computational domain to remove the spurious numerical reflections. The three-dimensional code is first validated for 2-D and 3-D cascades with harmonic vortical inlet distortions. The effectiveness of non reflecting boundary conditions is demonstrated. The unsteady Euler solver is then used to simulate the propagation of nozzle wake and secondary flow through rotor and the resulting unsteady pressure field in an axial turbine stage. The three dimensional and time dependent propagation of nozzle wakes in the rotor blade row and the effects of nozzle secondary flow on the rotor unsteady surface pressure and passage flow field are studied. It was found that the unsteady flow field in the rotor is highly three-dimensional and the nozzle secondary flow has significant contribution to the unsteady pressure on the blade surfaces. Even though the steady flow at the midspan is nearly two-dimensional, the unsteady flow is 3-D and the unsteady pressure distribution can not by predicted by a 2-D analysis.

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