The Experimental Study and Numerical Simulation of the Gas Flow Field in the Cold Storage of Procambarus Clarkii

2014 ◽  
Vol 716-717 ◽  
pp. 780-784
Author(s):  
Shuo Li ◽  
Shu Cai Wang ◽  
Fang Cheng ◽  
Gao Bing Xia

The gas flow in the cold storage plays a very important role in the effect of cold storages of procambarus clarkii. Only the reasonable gas flow ensures the uniform temperature field.The paper uses the technique of computational fluid dynamics (CFD) to conduct the numerical simulation of the flow field and finds out the law of the distribution of the temperature field,on the basis of which the numerical simulation of non steady state of the freezing process of the frozen products is carried out.The experiments prove that the simulation results can better reflect the reality,and show that CFD tools can play an important role in the design and optimization of cold storages.

2021 ◽  
Vol 261 ◽  
pp. 01040
Author(s):  
Xiaochuan Deng ◽  
Fengchang Sun ◽  
Zhonghua Bai ◽  
Zongze Yu ◽  
Jiahua Wu ◽  
...  

The complex structure of double inlet gas flue has a significant influence on gas flow field distribution in a 1000MW coal-fired boiler’s low temperature economizer. In order to optimize gas flow field of the low temperature economizer with double inlet gas flues and reduce its failure rate, this paper presents a flow field simulation of the low temperature economizer based on the computational fluid dynamics (CFD). This numerical simulation was operated by using porous media model instead of the complex structure inside heat exchanger and the standard k-epsilon model. Velocity contours of a same vertical cross-section inside of inlet gas flue of the heat exchange zone in different numerical simulations were evaluated by the evaluation standard of RSM. The results of numerical simulation show that the main reasons for uneven distribution of flow field in economizer and its inlet gas flues are unequal diameter of flue elbow and straight flue, unreasonable setting of guide plate and diffusion flue elbow. After making structural optimization of the low temperature economizer such as equalizing elbow to the straight flue diameter and setting the guide plate reasonably, the flow field in the low temperature economizer and its flues are obviously improved.


2012 ◽  
Vol 550-553 ◽  
pp. 3194-3200
Author(s):  
Guang Cai Gao ◽  
Jian Jun Wang ◽  
You Hai Jin

The gas flow field in the swirl tube was studied by experimental measurement and numerical simulation. The results show that the simulation results based on the Reynolds stress turbulent model is in good agreement with the measured results probed by the five orifice Pitot-tube. Meantime, it is analyzed that there is short cut stream at the end of the exit tube, and at the dust discharge jaws, the particles are prone to be re-entrained from the hopper. All results above provide a base for further research on the optimization of the structure and the improvement of the separation performance of the swirl tube.


2014 ◽  
Vol 1030-1032 ◽  
pp. 1352-1355
Author(s):  
Li Long Dong ◽  
Wei Lin Zhao ◽  
Jian Rong Wang ◽  
Zong Jun Geng

The paper presented the gas flow field and particle trajectory with a series of inner cylinders in cyclone preheater using RNG k-ε turbulence model and stochastic trajectory model on the platform of Fluent software. The separability and pressure loss of cyclone preheater were investigated. The result shows the ratio of d/D and h/H of cyclone preheater was advised 0.50 to 0.65 and 0.35 to 0.60 respectively. It is also found that the numerical simulation results are in agreement with the thermal data of cement plant.


2016 ◽  
Vol 680 ◽  
pp. 82-85
Author(s):  
Jian Cai ◽  
Lan Chen ◽  
Umezuruike Linus Opara

OBJECTIVE To investigate the influence of mesh type on numerical simulating the dispersion performance of micro-powders through a home-made tube. METHODS With the computational fluid dynamics (CFD) method, a powder dispersion tube was meshed in three different types, namely, tetrahedral, unstructured hexahedral and prismatic-tetrahedral hybrid meshes. The inner flow field and the kinetic characteristics of the particles were investigated. Results of the numerical simulation were compared with literature evidences. RESULTS The results showed that using tetrahedral mesh had the highest computational efficiency, while employing the unstructured hexahedral mesh obtained more accurate outlet velocity. The simulation results of the inner flow field and the kinetic characteristics of the particles were slightly different among the three mesh types. The calculated particle velocity using the tetrahedral mesh had the best correlation with the changing trend of the fine particle mass in the first 4 stages of the new generation impactor (NGI) (R2 = 0.91 and 0.89 for powder A and B, respectively). Conclusions Mesh type affected computational time, accuracy of simulation results and the prediction abilities of fine particle deposition.


2014 ◽  
Vol 6 ◽  
pp. 853069 ◽  
Author(s):  
Dong Liu ◽  
Ying-ze Wang ◽  
Hyoung-Bum Kim ◽  
Fang-neng Zhu ◽  
Chun-lin Wang

The wavy vortex flow in the plain model was studied by experimental measurement; the preliminary feature of wavy vortex flow was obtained. This flow field in the plain model was also studied by numerical simulation. The reliability of numerical simulation was verified by comparing with the experimental and numerical simulation results. To study the slit wall effect on the wavy vortex flow regime, another two models with different slit number were considered; the slit number was 6 and 12. By comparing the wavy vortex flow field in different models, the axial fluctuation of Taylor vortices was found to be different, which was increased with the increasing of slit number. The maximum radial velocity from the inner cylinder to the outer one in the 6-slit number was increased by 12.7% compared to that of plain model. From the results of different circumferential position in the same slit model, it can be found that the maximum radial velocity in slit plane is significantly greater than that in other planes. The size of Taylor vortices in different models was also calculated, which was found to be increased in the 6-slit model but was not changed as the slit number increased further.


2000 ◽  
Author(s):  
M. Modigell ◽  
M. Weng

Abstract The present paper proposes a new approach to analyse the conversion of complexly composed particles that are dispersed in a cyclone gas flow at high temperatures. The numeric simulation of flow field and particle trajectories is coupled with a thermodynamic equilibrium calculation which describes the particle reaction progress. First simulation results and the comparison with experimental data are shown in this paper.


2016 ◽  
Vol 43 (9) ◽  
pp. 0901007
Author(s):  
朱能伟 Zhu Nengwei ◽  
方晓东 Fang Xiaodong

2019 ◽  
Vol 33 (24) ◽  
pp. 1950279
Author(s):  
Xinhua Song ◽  
Xiaojie Li ◽  
Yang Wang ◽  
Honghao Yan

In this paper, a computational fluid dynamics–discrete element method (CFD–DEM) coupling method is established to simulate the starch granule injection by coupling CFD and DEM. Then a gas–solid two-phase pulsed jet system is designed to capture the flow field trajectory of particle injection (colored starch with a mean diameter of 10.67 [Formula: see text]m), and the image is processed by color moment and histogram. Finally, the simulation results are compared with the experimental results, and the following conclusions are drawn. The numerical simulation results show that with the increase of injection pressure, the injection height increases gradually. When the injection pressure reaches above 0.4 MPa, the increase of injection height decreases. The experimental images show that the larger the pressure (i.e., the greater the initial velocity), the faster the velocity of particle distribution in the space, and the injection heights with the injection pressures of 0.4 MPa and 0.5 MPa are close, which is consistent with the result from the FLUENT numerical simulation based on CFD–DEM.


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