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a,*ghufrankahdem@gmail.com, bahmed.shakir@qu.edu.iq Keywords: Microchannel; Laminar; Heat transfer; CFD simulation; Thermal analysis.
Numerical approach CFD simulations involve the use of computer software to model the movement of fluids inside a microchannel.
The accuracy of CFD simulations depends on the quality of the model input, including boundary conditions and fluid properties [17].
CFD analysis yields the following findings.
Simulations are dependent mainly on the mesh quality.

Here, we aim to demonstrate and analyze the gas film force based on simulations.
Using the open-source CFD software, OpenFOAM, a user-made C++ library was developed by authors to realize the dynamic updating of mesh and velocity on bearing surface.
Simulation Result and Discussion Our simulation results are present in term of dimensional quantities simply, and the load capacity of bearing is evaluated by the time-average film force per unit bearing surface measured in Pa.
The physic properties of air used as bearing medium in our simulation are listed as Table 2.
The film force increase was demonstrated and analyzed by means of numerical simulation.

Numerical simulations of spherical vertical-axis wind rotor Yongyu Huang1, a, Qiuyun Mo1, b, Xu Zhang1, Zupeng Zhou1 1School of Mechanical & Electrical Engineering, Guilin University of Electronic Technology, Guilin, Guangxi, China ahuangyy1022@mails.guet.edu.cn, bmoqyun@guet.edu.cn Keywords: Vertical axis wind rotor, Numerical simulation, Coefficient of wind power, Fluent.
This study will consider the output power coefficient Cp as target, and the numerical simulations for three different rotors having three blades as models of vertical axis wind turbines are conducted with CFD software.
Numerical simulation procedure Create model of blades.
Simulation results and analysis Different power coefficients have been applied to observe the rotational speed of the rotor.
Conclusions Three models of 2D and 3D are analyzed with CFD software by numerical simulation.

The prediction results from the standard Smagorinsky (LES-SML) and the dynamic structure (LES-DS) based LES turbulence model are mainly compared, while the commercial CFD software package ANSYS-Forte is employed for this purpose.
For literature reviews of numerical simulations, a faster speed of computational power makes the engine simulations with computational fluid dynamics (CFD) more efficient and reliable during the last few years. [5,6].
The commercial CFD software package namely ANSYS Forte [27] is used for this purpose.
The CFD mesh of the present study at time t = 1.5 ms is illustrated in Fig.2.
The commercial CFD software package namely ANSYS Forte was employed for this purpose.

Effects of the Test Models on the Supersonic Wind Tunnel Flow To analyze the influence of models in supersonic wind tunnels, simulations with the commercial CFD solver Star CCM+ from Siemens PLM Software were performed.
In Fig. 6, the total pressure curves of the best model support design and the worst model support design are compared with the simulation that contains only the test model without model support.
Fig. 6: Total pressure Curves of best and worst model support The total pressure curves of the simulation with the best model support and the simulation containing only the test model, are equal until to the position where the model support starts.
Fig. 7: Best and worst combination of the factors A, B, C and D Comparing the flow field of the simulations, with the model only and the best factor combination model support, the shockwave of the model is not influenced by the model support.
To evaluate the different factors, simulations with the CFD solver Star-CCM+ were computed for each model support design.

Taking a subway tunnel as the research object and based on the CFD simulation method, this paper adopts a large eddy simulation analysis software FDS to simulate and analyze the effect of exhaust velocity on fire smoke control under the condition of the same longitudinal ventilation velocity in subway tunnel.
Simulation scenarios are shown in Table 1.
When the simulation time is at 150s, the temperature got to increase.
At the end of the simulation, the temperature reached 65℃.
Thus, it makes the change of the temperature be measured earlier than that of visibility. 4 Conclusion Taking a section of 500m long subway tunnel as research object and based on CFD simulation method, this paper simulate and analyze the effect of different exhaust velocity on fire smoke control.

CFD approach was used with structure meshes to simulate the whole flow field of the pump, and make the performance prediction of the pump; The pressure released holes area are selected through theoretical and CFD analysis.
Numerical simulation and analysis Computational model.
Numerical simulation and experiment.
Approached by CFD numerical simulation, shown in Fig. 5 and Fig.6, if the sealing rings gap is certain, the pressure released holes area increases, then the leakage increase.
[5] Wang Fu-jun, Computational fluid dynamics analysis — CFD principles and application, Beijing:Tsinghua University Press, 2004 (in Chinese)

Hence, reliable and accurate CFD simulations can be interesting for turbines' manufacturers.
Our work is inspired by many authors interested in numerical simulation of wet steam flow, e.g. [1], [2], [3], [4], [5], [6].
In our result the start of pressure rise (Wilson region) is shifted slightly downstream, but similar result was achieved by numerical simulation in the original paper [10] and by other authors as well, e.g.
It is interesting that by modifying of perfect gas model, not very different result is obtained comparing to state-of-the-art equation of state provided by IAPWS-95 or equation of state for CFD purposes.Fig. 1: Mesh for numerical simulation Fig. 2: Detail of mesh near leading edge (left) and trailing edge (right) Fig. 3: Static pressure on blade surface (left), detail of condensation shock (right)Fig. 4: Mach number in domain with M = 1 (left), 50 contours of Mach number (right) Fig. 5: Wetness in domain with saturation boundary S = 1 (left), 25 contours of wetness (right) In the following only results achieved by implementing equation of state for CFD purposes are presented.
Conclusion The main goal was implementation of real equation of state into our in-house CFD code which solves wet steam flow with non-equilibrium condensation.

The study had gave an insight for the bubble growth and provided critical information for the theoretical modelling and numerical simulation [9].
The bubble formation and growth were included into the fluid flow simulation.
In addition, the models for bubble nucleation and growth were implemented into the CFD codes to predict the bubble formation and growth phenomenon.
Pressure based algorithm was employed in current work to calculate the hydrodynamics phenomenon through CFD codes.
Result and discussion The CFD simulation of bubble formation and growth across an orifice had successfully being simulated.

A 17-27-5 type BP neural network model was built, whose sampled data was got by hydrocyclone separation experiments; another 6-30-5 type BP neural network was also built, whose sampled data came from the simulation results of the LZVV of a hydrocyclone with CFD code FLUENT.
According to the same structural parameters, operational parameters and experimental material parameter of hydrocyclone, structural style of hydrocyclone’s LZVV was modeled [2] utilizing commercial CFD code fluent aimed to obtain another group of data sample , then two BP neural network models were built respectively.
Modeling BP neural network model according to hydrocyclone simulation data Dz Lz Fig. 3 LZVV self-defined parameter There are two different areas in hydrocyclone flow field, whose vertical velocity direction is just the opposite.
The LZVV structure [3] shown in fig.3 is obtained by simulating hydrocycle flow field using commercial CFD code FLUENT, whose inner surface is a homologous cone surface.
Separation performance was predicted utilizing the 6-30-5 type neural network and comparative analysis was done between simulation results and the predicted results.