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Influence of the fins on the Static Stability of autonomous underwater vehicle Minglong Huang1, a, Yuhong Liu1, Hongwei Zhang1, Baosheng Duan2 1School of Mechanical Engineering, Tianjin University, Tianjin 300072, China 2China Oilfield Services Limited Stock Company, Tianjin 300451, China ahuangminglong21@163.com Keywords: Autonomous underwater vehicle; fins; static stability; numerical simulation Abstract: Fins, which are mounted at the rear of the underwater vehicles, have the action of stabilizing.
Phillips [6] derived the steady state hydrodynamic derivatives of an AUV by using CFD to replicate the yawed towing tank and rotating arm experiments.
Results obtained from the CFD method were in agreement with those from the experiments.

Fig.3 The course of three-dimensional liner interpolation Fig.4 Sketch map of three-dimensional liner interpolation F The study of CFD numerical simulation and another measurement method Good mobility of modern fighter is beneficial for air combat.
CFD numerical simulation is used in these conditions to simulate movement of lubrication oil plane in oil tank with the change of aircraft attitude.
(4) VOF model is used to track phase interface of continuous media by means of CFD numerical simulation.

The Aerodynamic Characteristics of A Microbus Xiaoni Qia, Jian Mengb and Yongqi Liuc School of Vehicle and Transportation, Shandong University of Technology, Zhangzhou Road 12, Zibo 255049, China abmjw@163.com, bmengjian@163.com, yqliu@sdut.edu.cn Keywords: Aerodynamic Modeling; Microbus; CFD; Aerodynamic Shape.
The approach is the three dimensional (3-D) numerical simulation.
Numerical simulations on a microbus Mathematical model.
Fig.3-Sectional pathline distribution map I Fig.4-Sectional pathline distribution map II Conclusions After an analysis of simulation results, we can see that the external shape of the microbus has a great influence on the aerodynamic characteristics.

Turbulence model can be divided into the direct numerical simulation（DNS）, reynolds average method（RANS）and large eddy simulation (LES).
Simulation Models and Conditions Choice of the Model.
The simulation result error of WALE model is the largest.
An efficient very large eddy simulation model for simulation of turbulent flow.
CFD Let. 3(2011) 32-39

The governing partial differential equations of continuity and momentum were dicretised to algebraic equations by using CFD commercial code(FLUENT 6.3).
In the numerical work, CFD commercial code(FLUENT 6.3) using sliding mesh techniques was used to obtain the results.
,B.V.,1992“Pressure Fluctuation Numerical Simulation in a Centrifugal Pump Volute Casing,” Colloque C1, supplement au Journal de Physique III, Volume 2,PP.619-622
H., and Zhao, Z.M. , 2007, “Numerical Flow Simulation in a Centrifugal Pump at Design and Off-Design Conditions” International Journal of Rotating Machinery, Article ID 83641, 8 pages.

Based on the operating characteristics of a micro HCCI (Homogeneous Charge Compress Ignition) free-piston engine, a multidimensional model which coupled CFD code, chemical dynamic model and piston dynamic model has been established.
Meanwhile, working characteristics of micro engine generator are evaluated by employing the simulation result.
Simulation result provides essential requirements for micro free-piston engine control and design.
Assuming the flow of combustible gas in the clearance as a quasi-one-dimensional isentropic flow and for a certain component, its leakage mass is expressed as: (5) Simulation results analysis Simulation of ignition process.
To invest micro engine performance with different fuels, simulations of fuel to be methane, propane and hydrogen respectively are compared.

Computational Fluid Dynamics Computational Fluid Dynamics[1] (CFD for short) is based on classical fluid mechanics and numerical calculation method, through numerical calculation and image display, solving the whole flow field numerical, so as to achieve the purpose of the research on physical problems[2].
On the inside and outside the tube during the simulation calculation, differential pressure flow meter physical structure model using GAMBIT 2.2.30[4].
Papers finalized throttling ratio β of 0.6 for numerical simulation experiments show [5].
For the optimization and selection of tube inside and outside differential pressure flow meter, water is the simulation medium.
Simulation Results Analysis By the way of above pressure, we obtain four throttling ratios data.

Numerical Simulation Results Simulated Result and Analysis.
It has carried on resistance characteristic value simulation of inertial separator with 3 different kinds of turbulence models.
So the RNG model is more accurate for the numerical simulation of the inertial stage.
The experimental results validate the numerical simulation.
[4] Wang Fujun: Computational Fluid Dynamics-CFD Theory and Application, (Tsinghua University Press, Beijing 2004)

This study employs Fire Dynamics Simulation (FDS), fire simulation software, to construct model of thermal flow field.
This study adopts reinforced concrete beam as the subject, and it integrates two CFD numerical simulation software’s to analyze thermal flow field in a building’s fire field and temperature field inside the beam.
Firstly, FDS fire simulation software simulates a segment of the beam undergoing a fire.
Temperature distribution of 60 minutes’ simulation time is shown as Figure 3.
The temperature curves of simulation results are shows as Figure 4.

In terms of proper initial and boundary conditions, a simultaneous iterated solution process coupling governing equations and compensatory terms is carried out within the SIMPLEC algorithm in the CFD (Computational Fluid Dynamics) program FLUENT.
The program FLUENT, which is an excellent flow modeling simulation tool, allows us to obtain valuable information during casting process of the molten Al-alloy within the mould.
The initial conditions in this simulation are presented as: the temperature of the mould and the molten Al-alloy are 620 °C and 720 °C, respectively.
Fig.3 (b) shows the simulations of molten Al-alloy infiltrating throughout the mould at time t=0.2 s and t=0.5s.
Summary The considered examples of simulation indicate that CFD program (Fluent) can be treated as an attractive and useful tool for modelling the pressure infiltration casting process to produce open-cell metal foam.