CFD-based study of the abrasive flow characteristics within constrained flow passage in polishing of complex titanium alloy surfaces

2018 ◽  
Vol 333 ◽  
pp. 209-218 ◽  
Author(s):  
Li Zhang ◽  
Zhimin Yuan ◽  
Zijian Qi ◽  
Donghai Cai ◽  
Zhichao Cheng ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Flow Characteristics ◽  
Flow Passage ◽  
Constrained Flow

Research on the Periodicity of Flow Field in a Compressor Sector Cascade

2020 ◽  
Author(s):  
Wenfeng Xu ◽  
Peng Sun ◽  
Guogang Yang
Keyword(s):  
Flow Field ◽  
Design Method ◽  
Flow Characteristics ◽  
Suction Side ◽  
Low Energy ◽  
Experimental Conditions ◽  
Flow Passage ◽  
Aerodynamic Parameters ◽  
Real Flow ◽  
Annular Cascade

Abstract Sector cascade experiments can not only be convenient to measure various aerodynamic parameters but also reveal the real flow characteristics in turbomachinery. However, the sector cascade is only a part of the whole annular cascade. The circumferential angle, the structure of the side guide plate (SGP) and the suction mode on the SGP have a great effect on the periodicity of the flow field. Therefore, the effect of structure on periodicity must be taken into consideration in order to obtain accurate data of the sector cascade experiment. In this paper, a compressor sector cascade composed of a row of adjustable guide vanes (AGVs) and a row of stators is designed. The effect of the circumferential angle, SGP structure and suction position on the periodicity is studied by numerical simulation. An optimal cascade scheme is selected for experimental research. The results show that a larger circumferential angle can weaken the effect of low-energy fluid near the SGP on the middle passages. However, given the limited experimental conditions, the circumferential angle is set at 110° which consists of 15 AGVs and 14 stators. What’s more, the SGP with the same bowed angle of AGV on both sides of the cascade can reduce the influence of the SGP on the adjacent passages and obtain a regular periodicity. The low-energy fluids still accumulate near the SGP. The suction near the stator suction side of the SGP can alleviate the blockage in the flow passage and further improve the periodicity of the cascade. Serious analysis of the experiment results have further identified that the suction near the stator suction side of SGP can make the aerodynamic parameters of the flow field uniform and lead to a good periodicity. At the same time, the feasibility of this design method is verified.

Research on Flow Characteristics of Aerostatic Circular Thrust Bearing with a Cone Cavity

2011 ◽  
Vol 308-310 ◽  
pp. 189-192
Author(s):  
Long Xing Chen ◽  
Wen Qi Ma ◽  
He Chun Yu ◽  
Hai Yan Liu ◽  
Hong Wang Du
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Thrust Bearing ◽  
Single Point ◽  
Flow Characteristics ◽  
Simulation Method ◽  
Flow Passage ◽  
Testing Method ◽  
Measurement Results ◽  
Simulation And Experiment

The aerostatic circular thrust bearing was taken as a study subject. The numerical simulation method was used to calculate the flow passage. Meanwhile, the single-point testing method was used to test the pressure distribution. The simulation and experiment measurement results were compared and analyzed. The results show that: The single-point testing method is effective to capture the change of flow characteristics. The overall results of simulation and testing coincide with each other well. In the range of cone cavity, the flow pattern for the gas is turbulent flow, and the flow field should be divided into different zones for simulation.

Prediction of Flow Field in a MCFC Stack With Channels of Complex Shape

2004 ◽  
Author(s):  
D. N. Ryu ◽  
D. H. Choi
Keyword(s):  
Flow Field ◽  
Finite Volume ◽  
Complex Geometry ◽  
Flow Characteristics ◽  
Molten Carbonate Fuel Cell ◽  
Molten Carbonate ◽  
Flow Passage ◽  
Volume Calculation ◽  
Multiple Cell ◽  
Periodic Module

The flow passage in a molten-carbonate-fuel-cell (MCFC) stack consists of the cathode/anode channels of complex geometry and the inlet/outlet manifolds that supply and collect the gas to and from the channels. It is one of the major design concerns that the reacting fluid be uniformly distributed to each cell and to various regions of the electrode surface in the channel. The paper outlines the method to predict the flow characteristics in the flow passage of a multiple cell MCFC system. Rather than trying to obtain the finite volume solution over the entire channel directly, the channel with uniformly distributed trapezoidal shape supports is approximated by the equivalent porous medium. The effective permeability and the inertial resistance factor are estimated from a rigorous 3D finite volume calculation for a single periodic module of the channel. The pressure in the manifold is determined iteratively from the empirical head-loss relation in a tube. The volume change of the fluid due to chemical reaction is taken into consideration in the analysis. It is shown in the paper that the flow field in both cathode and anode channels is successfully computed and the mass flux to each cell can also be predicted. The pressure drop versus the flow rate for different stack-manifold arrangements is also discussed in the paper.

Internal Flow Characteristics of a Francis Hydro Turbine Model by Internal Flow Passage Shapes

2015 ◽  
Vol 18 (5) ◽  
pp. 19-25
Author(s):  
Zhenmu Chen ◽  
Qingsheng Wei ◽  
Patrick Mark Singh ◽  
Young-Do Choi
Keyword(s):  
Flow Characteristics ◽  
Internal Flow ◽  
Flow Passage ◽  
Hydro Turbine ◽  
Turbine Model

A Note on the Comparative Analysis Between Rectangular and Modified Duct Heat Exchanger

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Rajneesh Kumar ◽  
Varun Goel ◽  
Anoop Kumar
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Flow Characteristics ◽  
Radius Of Curvature ◽  
Transfer Enhancement ◽  
Rectangular Array ◽  
Flow Passage ◽  
Rounded Corner ◽  
The Cost ◽  
Similar Combination

Abstract The plate fin heat exchangers usually have either rectangular or triangular shaped flow passage. In comparison to triangular flow passage, rectangular flow passage gives comparatively higher heat transfer at the cost of higher pumping power. In the present investigation, flow passage is modified by rounding the corner of triangular passage to investigate the heat and flow characteristics of air flowing through it. Comparison of performance between modified and rectangular flow passage has also been presented and discussed. The radius of curvature of the rounded corner has been kept constant with value of 0.49 times duct height (H). The dimple was also fabricated at the inner side of the flow passage and arranged in rectangular array. Distance between them was defined by two different dimensionless parameters, relative transverse width (x/h), and relative streamwise length (z/h), whereas, dimensionless height of the protrusion is defined by relative dimple height (h/D). Noticeable increment in both heat transfer and friction factor has been observed by modifying the duct corners and 2.98 times increment in Nusselt number resulted due to dimples in modified duct for h/D, x/h, and y/h value of 0.44, 10, and 10, respectively, in comparison to smooth duct at Reynolds number of 19,500. For similar combination of roughness parameters, highest frictional penalty was estimated with value of 4.46 times that of the smooth duct at Reynolds number of 4400. Additionally, the comparative assessment of heat transfer enhancement (Nuenh), frictional penalty (fpenalty), and thermohydraulic performance index (THPi) has also been carried out to understand the suitability of round cornered duct. In comparison to protruded rectangular duct, 28% higher THPi is obtained in modified duct under similar conditions.

Sign in / Sign up

Export Citation Format

Share Document