scholarly journals Numerical Prediction of Homogeneity of Gas Flow through Perforated Plates

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1770
Author(s):  
Kamil Śmierciew ◽  
Dariusz Butrymowicz ◽  
Jarosław Karwacki ◽  
Jerzy Gagan

Vanes and baffles are often used as flow distributors where uniform flow is required in the apparatus of large cross-section surface areas. As an alternative, perforated plates with a range of open area ratios are applied to produce required gas flow homogeneity. Usually, the plates with various open area ratios are combined into large panels, of which total surface area can reach hundreds of square meters for large-sized industrial apparatus. Numerical modelling of the flow through such panels can be thought of as overly complex, time-consuming, and inefficient due to numerous small open area ratios in the plates and large differences in dimensions between open area ratios and free-stream areas. For this reason, numerical models of gas flow are limited to single plates only with constant open area ratios. A new indirect modelling approach of gas flow through the perforated plates panel with structural elements and various open area ratios with application of the porous media model is proposed. A perforated plate was experimentally investigated in terms of pressure drop and velocity distribution. The data obtained were used for the validation of the numerical results, which differed from the experimental results by less than 5%. In the next step, numerical analyses were performed for plates with open area ratios in the range of 30 to 70% for gas velocities of 5 and 10 m/s. A general correlation for pressure drop as a function of open area ratio was proposed. Finally, systematic numerical studies of the flow through both perforated and porous plates including structural elements were performed. The internal resistance of the porous core was calculated by means of a developed correlation. A good agreement between results with an error lower than 15% was observed.

1960 ◽  
Vol 64 (590) ◽  
pp. 103-105
Author(s):  
P. G. Morgan

The flow through porous screens has been widely studied from both the theoretical and experimental points of view. The most widely used types of screen are the wire mesh and the perforated plate, and the majority of the literature has been concerned with the former. Several attempts have been made to correlate the parameters governing the flow through such screens, i.e. the pressure drop, the flow conditions and the geometry of the mesh.


Author(s):  
Dejan Brkić

Today, two very efficient methods for calculation of flow distribution per branches of a looped gas pipeline are available. Most common is improved Hardy Cross method, while the second one is so-called unified node-loop method. For gas pipeline, gas flow rate through a pipe can be determined using Colebrook equation modified by AGA (American Gas Association) for calculation of friction factor accompanied with Darcy-Weisbach equation for pressure drop and second approach is using Renouard equation adopted for gas pipeline calculation. For the development of Renouard equation for gas pipelines some additional thermodynamic properties are involved in comparisons with Colebrook and Darcy-Weisbach model. These differences will be explained. Both equations, the Colebrook’s (accompanied with Darcy-Weisbach scheme) and Renouard’s will be used for calculation of flow through the pipes of one gas pipeline with eight closed loops which are formed by pipes. Consequently four different cases will be examined because the network is calculated using improved Hardy Cross method and unified node-loop method. Some remarks on optimization in this area of engineering also will be mentioned.


Author(s):  
Michael James Martin

Gas flow through arrays of rectangular nano-fins is modeled using the linearized free-molecular drag and heat transfer equations. These are combined with the one-dimensional equations for conservation of mass, momentum, and energy, and the ideal gas law, to find the governing equations for flow through the array. The results show that the pressure gradient, temperature, and local velocity of the gas are governed by coupled ordinary differential equations. The system of equations is solved for representative arrays of nano-fins to find the total heat transfer and pressure drop across a 1 cm chip.


Author(s):  
Kunihiko Ishihara ◽  
Masanori Nakaoka

Vortices occur when gas flow passes through a duct with a tube bank of heat exchangers, such as a gas heater and/or a boiler. Very high level noise called a “self-sustained tone” occurs due to the interference of the vortices and the sound field in the duct. In general, baffle plates are used to suppress the self-sustained tone. However, it is difficult to use them effectively, because insertion conditions are vague. Then, perforated plates are used in both sides of the duct walls to suppress the self-sustained tones. Because we thought that the perforated plate might have acoustic damping and resonance mode of the duct perpendicular direction to the flow may be suppressed by its damping effect, when the self-sustained tone occurred. Some experiments were carried out to examine the suppression effect of the perforated plates installed. As a result, the suppression effect appeared in all cases. The purpose of this study is to clarify the effectiveness of the perforated plates for self-sustained tones.


Author(s):  
Shripad A Upalkar ◽  
Saksham Gakhar ◽  
Shankar Krishnan

Abstract This paper reports a mathematical model for predicting the fluid and heat flow characteristics of a Z-shaped corrugated perforated plate heat sink. Experiments were carried out to validate overall pressure drop as well as heat transfer predictions. A two-pronged approach was undertaken to design a corrugated perforated fin geometry: (a) macroscopic packaging, where the flow is distributed into conduits before being fed into perforated plates, and (b) microscopic design, where the pores are sized to maximize heat dissipation. A methodology typically used for predicting flow maldistribution is extended for packaging porous perforated plates in the macroscopic approach. An illustrative study is carried that estimates the optimum number of porous perforated plate fins that can be packaged within a given volume under fixed pressure drop constraint. In the microscopic approach, an order of magnitude analysis was carried out to decide the optimum diameter to maximize the heat transfer rate and expression for optimum diameter, and maximum achievable heat flux is proposed. Numerical simulations were carried out by considering full perforated plate porous fin geometry and single-channel geometry, and good agreement in their results was found. Finally, this study elaborates on the importance of achieving uniform flow distribution across the porous perforated plate fins.


Author(s):  
S. Lai´n ◽  
M. Sommerfeld

The structure of particle-laden gas flows in a horizontal-to-vertical elbow is investigated numerically for analysing the required modelling depth. The numerical computations are performed with the fully coupled Euler-Lagrange approach considering all the relevant forces: drag, gravity-buoyancy and lift forces (slip-shear and slip-rotational). Moreover, interparticle and particle-rough wall collisions are taken into account by means of stochastic approaches. The effect of the different mechanisms, i.e. wall roughness, inter-particle collisions and mass loading, on the flow structure in the bend and the resulting pressure drop are investigated.


2020 ◽  
Vol 98 (10) ◽  
pp. 2238-2256
Author(s):  
Min Qiao ◽  
Shaobei Liu ◽  
Weixing Huang ◽  
Renjie Hao ◽  
Taoxian Zhang ◽  
...  

Author(s):  
Milka Hebi Nava Rivera ◽  
Daisuke Ito ◽  
Yasushi Saito ◽  
Mitsuhiro Aoyagi ◽  
Kenji Kamiyama ◽  
...  

Two-phase flow through porous media should be well understood to develop a severe accident analysis code not only for light water reactor but also sodium cooled fast reactor (SFR). When a core disruptive accident occurs in SFR, the fuel inside the core may become melted and interacts with the coolant. As a result, gas-liquid two-phase flow will be formed in the debris bed, which may have porous nature depending on the cooling process. Thus, as first step, present work focuses on the characteristics of pressure drop in single- and two-phase flows in different porous media conditions (porous size, liquid and gas flow velocity). In addition, in order to construct an experimental database, the measured pressure drop under different conditions was compared with existing correlations.


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