Sensitivity of the CFD Mesh for a Single Rising Bubble in a Hallimond Tube

2013 ◽  
Vol 372 ◽  
pp. 26-29 ◽  
Author(s):  
Ashraf Azmi ◽  
Periyasamy Balasubramanian ◽  
Bawadi Abdullah ◽  
Ehsan Zhalehrajabi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Axial Velocity ◽  
Pressure Coefficient ◽  
Simulated Data ◽  
Rigid Sphere ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Rising Bubble ◽  
Simulation Results

This paper presents how a single rising bubble experiment in the Hallimond Tube (HT) can be predicted using a computational fluid dynamics model (CFD). The study is emphasized on the effect of CFD Mesh to the pressure coefficient and axial velocity around the bubble. A rigid sphere with the radius of 0.00575 m using flow velocity of 0.0067 m/s was considered in this study. Experimental and simulated data obtained by other researchers in the similar study were used to validate the simulation results from the computational fluid dynamics model.

scholarly journals Numerical simulation of performance and emission of marine diesel engine under different gravity conditions

2020 ◽  
Vol 12 (7) ◽  
pp. 168781402092750
Author(s):  
Xiuwei Lu ◽  
Peng Geng
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Computational Fluid Dynamics ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Marine Diesel ◽  
Simulation Results

A computational fluid dynamics model of the marine diesel engine was established and validated, and the simulation studies were carried out using this model. Different gravity conditions were set in the computational fluid dynamics model to investigate their effect on marine diesel emissions and performance. By comparing the simulation results under different basic grid sizes, 1.2 mm was selected as the basic grid size of the computational fluid dynamics model. The model uses the experimental data including cylinder pressure, heat release rate, and nitrogen oxides (NO x) emissions to calibrate and validate the model. The simulation results are very close to the experimental data, and slight errors are also within the allowable range. In particular, when considering the heat transfer of the combustion chamber wall, the simulation results of the heat release rate are closer to the experimental data. The simulation results show that gravity has a slight effect on cylinder pressure and heat release rate, and has a certain degree of effect on fuel spray and atomization. The penetration length of the fuel is proportional to the gravity, and the maximum deviation of the Sauter mean diameter of the droplet is 25.74%. The spray and atomization process of fuel directly affects combustion and emissions. The maximum deviation of NO x emissions is 6.03%, which is reduced from 7.46 to 7.01 g/kW·h. Finally, the three-dimensional simulation results of temperature, equivalence ratio, and NO x emission of different crank angles under different gravity conditions are compared.

scholarly journals Computational Fluid Dynamics Model on Updraft Gasifier Using Carbonized Woody Briquette as Fuel

2017 ◽  
Vol 142 ◽  
pp. 166-171 ◽  
Author(s):  
Ding Lu ◽  
Kunio Yoshikawa ◽  
Tamer M. Ismail ◽  
M. Abd El-Salam
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model
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