Mathematical Fluid Dynamics of Store and Stage Separation, Multi-Body Flows and Flow Control

2008 ◽  
Author(s):  
Norman D. Malmuth ◽  
Alexander V. Fedorov
Keyword(s):  
Fluid Dynamics ◽  
Flow Control ◽  
Stage Separation ◽  
Multi Body

Computational Fluid Dynamics Prediction of Hyper-X Stage Separation Aerodynamics

2001 ◽  
Vol 38 (6) ◽  
pp. 820-827 ◽  
Author(s):  
Pieter G. Buning ◽  
Tin-Chee Wong ◽  
Arthur D. Dilley ◽  
Jenn L. Pao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Stage Separation

Initial Findings on the Feasibility of Real-Time Feedback Control of a Hazardous Contaminant Released Into Channel Flow by Means of a Laboratory-Scale Physical Prototype

2014 ◽  
Author(s):  
Sara P. Rimer ◽  
Nikolaos D. Katopodes ◽  
April M. Warnock
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Control ◽  
Real Time ◽  
Public Spaces ◽  
Control Model ◽  
Toxic Chemicals ◽  
Current State ◽  
Physical Prototype ◽  
Computational Fluid Dynamics Cfd

The threat of accidental or deliberate toxic chemicals released into public spaces is a significant concern to public safety. The real-time detection and mitigation of such hazardous contaminants has the potential to minimize harm and save lives. We develop a computational fluid dynamics (CFD) flow control model with the capability of detecting and mitigating such contaminants. Furthermore, we develop a physical prototype to then test the computer model. The physical prototype is in its final stages of construction. Its current state, along with preliminary examples of the flow control model are presented throughout this paper.

Investigation of vehicle stability under crosswind conditions based on coupling methods

2019 ◽  
Vol 233 (13) ◽  
pp. 3305-3317 ◽  
Author(s):  
Taiming Huang ◽  
Shuya Li ◽  
Zhongmin Wan ◽  
Zhengqi Gu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Large Eddy Simulation ◽  
Coupling Method ◽  
Vehicle Stability ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Body Dynamics ◽  
Multi Body ◽  
Vehicle Movement

In this study, vehicle stability under crosswind conditions is investigated. A two-way coupling method is established based on computational fluid dynamics and vehicle multi-body dynamics. Large eddy simulation is employed in the computational fluid dynamics model to compute the transient aerodynamic load, and the accuracy of the large eddy simulation is validated with a wind tunnel experiment. The arbitrary Lagrange–Euler technique is used in the computational fluid dynamics simulation to realise vehicle motion, and a real-time data transmission method is employed to ensure effective exchange of data between the computational fluid dynamics and multi-body dynamics models. The robustness of the two-way coupling model is verified by changing the position of the vehicle centroid. The results of the two-way and one-way coupling simulations demonstrate that crosswinds significantly affect vehicle stability. There is a clear difference between the results obtained with the two methods, particularly after the disappearance of the crosswind. The main reason for the difference is that the interaction between the transient airflow and the vehicle movement is considered in the two-way coupling method. Therefore, investigations of vehicle stability under crosswind conditions should consider the coupling of transient aerodynamic force and vehicle movement.

scholarly journals Combined simulation of heavy truck stability under sudden and discontinuous direction change of crosswind with computational fluid dynamics and multi-body system vehicle dynamics software

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878636
Author(s):  
Zhe Zhang ◽  
Jie Li ◽  
Wencui Guo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Closed Loop ◽  
System Simulation ◽  
Open Loop ◽  
Lateral Acceleration ◽  
Body System ◽  
Direction Change ◽  
Heavy Truck ◽  
Multi Body

The method of yaw model is used to establish aerodynamic property of heavy truck in computational fluid dynamics and wind tunnel test. A model of multi-body system simulation for heavy truck is built based on design and measure data from body, driving system, steering system, braking system, and powertrain system with TruckSim. Aerodynamic reference point of Society of Automotive Engineers (SAE) and aerodynamic coefficients are as the interface to integrate computational fluid dynamics and multi-body system simulation. A sudden and discontinuous direction change of crosswind is set up in multi-body system simulation, and dynamic performance of the heavy truck is performed by open-loop and closed-loop simulation. Under the given simulation case, lateral offset of the truck for open-loop simulation is 1.55 m and more than that for closed-loop simulation; the roll rate range of both simulations is −1.49°/s to 1.695°/s, the range of lateral acceleration is −0.497 m/s2 to 0.447 m/s2 in open-loop simulation, the range of lateral acceleration is −0.467 m/s2 to 0.434 m/s2 in closed-loop simulation; the range of yaw rate is −1.36°/s to 1.284°/s in open-loop simulation, the range of yaw rate is −0.703°/s to 0.815°/s in closed-loop simulation. The results show that combined simulation of the heavy truck stability can be completed by computational fluid dynamics and multi-body system software under sudden and discontinuous direction change of crosswind.

On the application of passive flow control for cavitation suppression in torque converter stator

2019 ◽  
Vol 29 (1) ◽  
pp. 204-222 ◽  
Author(s):  
Cheng Liu ◽  
Wei Wei ◽  
Qingdong Yan ◽  
Brian K. Weaver ◽  
Houston G. Wood
Keyword(s):  
Fluid Dynamics ◽  
Flow Control ◽  
Torque Converter ◽  
Control Technique ◽  
Content Type ◽  
Passive Flow Control ◽  
Cavitation Process ◽  
Passive Flow ◽  
Stator Blade ◽  
Torque Converters

Purpose The purpose of this paper is to study the transient cavitation process in torque converters with a particular focus on cavitation suppression with a passive flow control technique. Design/methodology/approach The transient fluid field in a torque converter was simulated by RANS-based computational fluid dynamics (CFD) in a full three-dimensional (3D) model. A homogeneous Rayleigh–Plesset cavitation model was used to simulate the transient cavitation process and the results were validated with test data. Various secondary flow passages (SFP) were applied to the stator blade. The cavitation behavior and hydrodynamic performance were simulated and compared to investigate the effect of SFP geometries on cavitation suppression. Findings Presented results show that cavitation in the torque converter is highly unstable at stall operating condition because of the combination of a high incidence angle and high flow velocity. The addition of an SFP to the stator blade produces a disruption of the re-entrant jet and reduces the overall degree of cavitation, consequently inhibiting the unstable cavitation and reducing performance degradation. Originality/value This paper provides unique insights into the complicated transient cavitation flow patterns found in torque converters and introduces effective passive flow control techniques useful to researchers and engineers in the areas of fluid dynamics and turbomachinery.

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