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Numerical Simulation of Unsteady Aerodynamic Loads over an Aerofoil in Transonic Flow Yu Qian1, a, JunLi Yang1,b XiaoJun Xiang1,c and MingQiang Chen1,d 1Civil Aviation Flight University of China, Guanghan Sichuan 618307, China aqianyucafuc@hotmail.com, byjl_tom@163.com, cxj_xiang@126.com,dmq_chen@126.com Keywords: numerical simulation, unsteady flow, hysteresis effect, hysteresis loop Abstract.
Generally, there are three traditional approaches to determine the stability and control characteristics: flight testing, wind-tunnel testing and Computational Fluid Dynamics (CFD).
A reasonable compromise between testing procedures and semi-empirical approaches is CFD, which represents the state of the art in modeling non-linear flow physics.
CFD solvers have reached a level of robustness and maturity to allow routine use on relatively inexpensive computer clusters.
Badcock, Computation of Dynamic Derivatives Using CFD.AIAA paper.

Asfour and Gadi [3] demonstrated the CFD is useful to predict the wind-driven natural ventilation in buildings and compared the implementation of computational fluid dynamics (CFD) and Network models for airflow rate estimation.
Gan [6] investigated the buoyancy-driven natural ventilation of buildings by CFD methods.
In this paper, the authors numerically investigated the natural ventilation in a workshop with heat sources based on CFD method.
Sketch of workshop ( 1: air inlet opening; 2: air outlet opening; 3: workshop entrance; 4: heat sources) Numerical model and simulation method.
Realizable k−ε turbulent model was selected for the CFD calculation after several trial calculations and comparison to related experimental data.

., Tianjin, 300457, China a Corresponding author, Email: zsha@tust.edu.cn Keywords: Multi-scale; Solid-liquid two-phase flow; Vortex; CFD.
Computational fluid dynamics (CFD) method was used to study the inhomogeneous distribution and multi-scale features of the solid particles in DTB crystallizer.
These years, as a research approach, CFD has been widely used in simulation industrial crystallization process [6,7].
In order to simplify the simulation, only the main forces shape resistance and drag force are taken into consideration.
Geometry and meshes of DTB crystallizer in simulation In the simulation process, water (density 997 kg/m3) worked as continuous phase.

CFD: Computational Fluid Dynamics.
DES: Detached Eddy Simulation.
They examined classical BEM theory and the modified BEM as well as CFD and the BEM-CFD mixed method.
RANS simulations of transitional flow by γ model.
Introduction of a modified segregated numerical approach for efficient simulation of γ-Reθt transition model.

In recent years, with the rapid development of computer technology, make using Computational Fluid Dynamics (CFD) technology simulation water-oil separation hydrocyclone flow field in possible.
More and more scholars have focused on investing internal flow field and complex geometries of hydrocyclone using principle and method of CFD which allow the simulation of very complex flow problems without the expense of experimental setup and measurements.
Numerical simulation Model parameters.
Fig. 2 CFD mesh for the hydrocyclone Results and analysis Fig. 3 reflects the trajectory about the water-oil two phase liquid flowing within hydrocyclone.
Cao, et al, “Numerical simulation of the effects of turbulence intensity and boundary layer on separation efficiency in a cyclone separator,”Chemical Engineering Journal 95 (2003) , p.235–240.

Steady cavity flow of 2-D hydrofoil is simulated by CFD software.
The impacts of different cavitation models, turbulence models and wall functions to the numerical simulation results are analyzed.
Simulation results were compared with experimental data under different cavitation number.
Summary and conclusions Factors which influence the accuracy of simulation results to cavitation flow were analyzed in this work.
The analysis of computation fluid dynamics—the based theory and application of CFD[M].

The numerical simulation of the vehicle was completed based on the theory of the aerodynamics.
Because of the cost and conditions in testing, recently, more attention is paid to CFD.
Computational Fluid Dynamics (CFD) is an attractive approach as it can provide a large amount of data and detailed information on the flow field.
Two vehicle-dynamics simulations were conducted for transient crosswind conditions.
Simulation Research on Automotive Aerodynamic Characteristics during the Overtaking Process[J].

In this study, commercial software ESI-CFD® was adopted for the simulation.
Results and Discussions Simulations of Static Pull-in.
The static and transient pull-in processes analyses were performed by using the ESI-CFD ®.
[9] CFD Research Corporation: CFD-ACE Theory Manual Ver.4.0 (Huntsville, AL 1998)
Beskok, Microflows and Nanoflows: Fundamentals and Simulation, New York: Springer-Verlag (2005).

Erosion Behavior of Blooie Line in Gas Drilling Dongli Lv1,a, Tao Zhang2,b 1School of Material Science and Engineering, Southwest Petroleum University, Chengdu 610500, China 2School of Oil & Natural Gas Engineering, Southwest Petroleum University, Chengdu 610500, China alvl393@163.com, bzhangt@swpu.edu.cn, Keywords: Gas drilling, Blooie line, Erosion, CFD, Erosion model.
Computational Fluid Dynamics (CFD) technology is adopted to solve the flow field in the bend pipe and the erosion laws of the pipeline wall are predicted coupling material erosion model.
CFD model There are three steps to simulate the erosion behavior of rock fragments entrained by the gas flow impacting the solid wall: CFD simulation of the gas flow field, the particle trajectory tracking and the erosion rate of the solid wall calculation.
In the step of the flow field simulation, the pipe flow distribution can be obtained by solving the Reynolds Averaged NS equation (RANS) and the closed turbulence model.
In the simulation of turbulent flow with a strong rotation, RNG turbulent model has higher precision.

Cyclic tests are commonly performed initially to characterize the device behavior but a full validation requires the simulation of realistic dynamic loads and the accurate reproduction of the real boundary conditions.
Fig. 1, Railway bridge protected by CFD devices.
Railway Elastomeric bearing CFD device Fig. 2, Physical substructure: CFD testing setup (left) and characterization of the CFD device at different internal pressure (right, from [5]).
The CFD device is placed between two fixed steel plates with the lower part of the device free to slide on a Teflon plate and with the upper part rigidly connected to the upper steel plate.
Assuming that isor is the value of the actuator force measured by the load cell at the level of the CFD device and that the isolator connects the 4th and the 6th DOF, the central difference algorithm [3] is implemented as illustrated in Fig. 4: Fig. 4, Basic on-line testing algorithm with substructuring The CFD device was first tested with a constant pressure of 60 MPa.