Numerical simulation of raindrops distribution on canopy surface of hemispherical parachute in heavy rain via two-phase flow approach

2016 ◽  
Vol 231 (4) ◽  
pp. 657-668 ◽  
Author(s):  
Jian Yue ◽  
Puyun Gao ◽  
Mingliang Zhang ◽  
Wenke Cheng
Keyword(s):  
Numerical Simulation ◽  
Two Phase Flow ◽  
Heavy Rain ◽  
Critical Value ◽  
Phase Flow ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Discrete Phase ◽  
Simulation Results ◽  
High Pressure Zone

The descent of parachute and re-entry capsule in heavy rain has been rarely researched yet. Study of raindrops distribution on canopy surface in heavy rain environment is a key step in the whole research. In this paper, the discrete phase model of two-phase flow approach is applied to simulate the raindrop trajectories in order to research the problem of raindrops distribution on canopy surface when parachute and re-entry capsule are descending in heavy rain. Numerous cases based on different rainfall rates and vertically descending velocities of a simple hemispherical parachute and re-entry capsule are numerically calculated preliminarily. The simulation results are presented, and it is found that the raindrops trapped by the canopy surface are not even-distributed, and raindrops are concentrated near the bottom edges of canopy surface as a result of high-pressure zone enclosed by the parachute; there is a corresponding critical value of descending velocity of parachute and re-entry capsule which determines whether the raindrops will be trapped by the canopy surface for one particular rainfall rate; only above the critical value of descending velocity of parachute and re-entry capsule the raindrops can be trapped by the canopy surface. The conclusions will be of great significance to the further research of the problem of descent of parachute and re-entry capsule in heavy rain.

Numerical Simulation for Two-Phase Flow Field of FGD Scrubber in Ship

2013 ◽  
Vol 739 ◽  
pp. 450-453
Author(s):  
Yong Zheng Gu ◽  
Zhi Feng Dong ◽  
Quan Jin Kuang ◽  
Jie Liu ◽  
Yu Zhao Zhang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Optimization Design ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Phase Flow ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Discrete Phase

Discrete phase model was used for three-dimensional numerical simulation of two-phase flow in the ship FGD scrubber. The κ-ε model and SIMPLE algorithm were adopted in the calculation. The results showed that adding porous baffles improved the distribution of flow field in the scrubber. The gas velocity in the scrubber became uniformity and the flue gas resistance decreased when the sprays worked. Under the action of the spray, the differential pressure of spray area changed greatly. The simulation plays a certain role in guiding the structural optimization design of scrubber.

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.

Aerodynamic Characteristics of NACA 23015 Landing Configuration with 20o Flap in Simulated Rain

2014 ◽  
Vol 555 ◽  
pp. 108-112
Author(s):  
Shahid Latif ◽  
Zhou Hong ◽  
Muhammad Ismail
Keyword(s):  
Heavy Rain ◽  
Aerodynamic Characteristics ◽  
Continuous Phase ◽  
Phase Flow ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Discrete Phase Modeling ◽  
Wall Film ◽  
Discrete Phase ◽  
Simulated Rain

In our numerical simulation the heavy rain effects have been studied on the aerodynamic performance of 2D cambered NACA 23015 airfoil landing configuration with 20o. We have used preprocessing software gridgen for creation of the landing configuration of the airfoil and then creating mesh around it. Fluent is used to solve the conservation equations. We have used discrete phase modeling (DPM) in Fluent to simulate the rain phenomenon in continuous phase flow by using two phase flow approach. In our study the coupling between the discrete and the continuous phase has been activated. In discrete phase model (DPM), we used the wall film model for the interaction of the continuous and discrete phase. The airfoil landing configuration exhibited significant decrease in lift and increase in drag for a given lift conditions in simulated rain. Post processing software like MATLAB, Tec plot and Origin are used to see the effects of the heavy rain and then results obtained are compared with the experimental results. Our numerical results in most of cases show similar trends with the experiments.

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.

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