scholarly journals Experimental and Computational Investigation of Intra- and Interlayer Space for Enhanced Depth Filtration and Reduced Pressure Drop

2020 ◽  
Vol 12 (41) ◽  
pp. 46804-46815 ◽  
Author(s):  
Sanghyun Roh ◽  
Minwoo Song ◽  
Kyeongeun Lee ◽  
Kangsoo Park ◽  
Jooyoun Kim
Keyword(s):  
Pressure Drop ◽  
Interlayer Space ◽  
Computational Investigation ◽  
Reduced Pressure ◽  
Depth Filtration

scholarly journals Design of Web-to-Web Spacing for the Reduced Pressure Drop and Effective Depth Filtration

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1822 ◽  
Author(s):  
Sanghyun Roh ◽  
Kangsoo Park ◽  
Jooyoun Kim
Keyword(s):  
Pressure Drop ◽  
Service Life ◽  
Air Gap ◽  
Design Solution ◽  
Air Filtration ◽  
Reduced Pressure ◽  
Practical Design ◽  
Depth Filtration ◽  
Effective Depth ◽  
Face Velocity

The study aims at lowering the pressure drop and extending the service life at a given set of filter materials implementing a space between the filter layers. As design factors, the web-to-web space was implemented by inserting either a bulk air gap or porous spacer web between the filter webs. The effect of spacing, either by the air gap or by the spacer web, on the pressure drop reduction was apparent for 4-layer constructions, and the effect was greater at the higher face velocity. The use of spacer web was more effective than the air gap in reducing the pressure drop, because the porous, fluffy spacer web acted as an effective air flow channel between the compact filter layers. The loading capacity was also increased with the spacer web implementation, effectively delaying the clogging point and extending the service life. Employing both experimental investigation and numerical simulation, this study intended to provide a practical design solution to the important problem in the field of air filtration. The results of this study can be used as a practical design guide to reduce pressure drop via depth filtration.

scholarly journals Erratum: Design of Web-to-Web Spacing for the Reduced Pressure Drop and Effective Depth Filtration. Polymers 2020, 11, 1882

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 938
Author(s):  
Sanghyun Roh ◽  
Kangsoo Park ◽  
Jooyoun Kim
Keyword(s):  
Pressure Drop ◽  
Reduced Pressure ◽  
Depth Filtration ◽  
Effective Depth ◽  
Published Paper

The authors wish to make a change to the published paper [...]

Heat Transfer Enhancement in a Rectangular (AR = 3:1) Channel With V-Shaped Dimples

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
C. Neil Jordan ◽  
Lesley M. Wright
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Liquid Crystal ◽  
Pressure Drop ◽  
Heat Transfer Enhancement ◽  
Thermal Performance ◽  
Secondary Flows ◽  
Transfer Enhancement ◽  
Reduced Pressure

An alternative to ribs for internal heat transfer enhancement of gas turbine airfoils is dimpled depressions. Relative to ribs, dimples incur a reduced pressure drop, which can increase the overall thermal performance of the channel. This experimental investigation measures detailed Nusselt number ratio distributions obtained from an array of V-shaped dimples (δ/D = 0.30). Although the V-shaped dimple array is derived from a traditional hemispherical dimple array, the V-shaped dimples are arranged in an in-line pattern. The resulting spacing of the V-shaped dimples is 3.2D in both the streamwise and spanwise directions. A single wide wall of a rectangular channel (AR = 3:1) is lined with V-shaped dimples. The channel Reynolds number ranges from 10,000–40,000. Detailed Nusselt number ratios are obtained using both a transient liquid crystal technique and a newly developed transient temperature sensitive paint (TSP) technique. Therefore, the TSP technique is not only validated against a baseline geometry (smooth channel), but it is also validated against a more established technique. Measurements indicate that the proposed V-shaped dimple design is a promising alternative to traditional ribs or hemispherical dimples. At lower Reynolds numbers, the V-shaped dimples display heat transfer and friction behavior similar to traditional dimples. However, as the Reynolds number increases to 30,000 and 40,000, secondary flows developed in the V-shaped concavities further enhance the heat transfer from the dimpled surface (similar to angled and V-shaped rib induced secondary flows). This additional enhancement is obtained with only a marginal increase in the pressure drop. Therefore, as the Reynolds number within the channel increases, the thermal performance also increases. While this trend has been confirmed with both the transient TSP and liquid crystal techniques, TSP is shown to have limited capabilities when acquiring highly resolved detailed heat transfer coefficient distributions.

Joint Numerical–Experimental Investigation of Enhanced Chemical Reactivity in Microfibrous Materials for Desulfurization

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Ravi K. Duggirala ◽  
Christopher J. Roy ◽  
Priyanka Dhage ◽  
Bruce J. Tatarchuk
Keyword(s):  
Pressure Drop ◽  
Chemical Reactivity ◽  
Chemical Conversion ◽  
Reaction Rates ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Pure Hydrogen ◽  
New Materials ◽  
Reduced Pressure ◽  
Negative Effect

Ultra-pure hydrogen is very much required for a healthy operation of proton exchange membrane (PEM) fuel cells. The concentration of sulfur in the fuel is an important controlling factor because it leads to pollution via sulfur oxides. H2S sorbent or catalysts coated on the particles that are in the order of 100 μm diameters entrapped into a high void volume carrier structure of sintered microfibers are observed to possess significantly higher heterogeneous reaction rates than packed beds of the small particle size. Fundamental reasons for this difference are investigated in this study to determine if such differences are caused by: (1) bed channeling, (2) microscale interstitial/interparticle velocity distributions, and/or (3) effect of presence of fibers. Since microscale fluid effects are not accounted for in traditional reaction engineering formulations, more rigorous approaches to the fluid flow, gaseous diffusion and surface reaction behaviors for a ZnO-based H2S sorbent have been undertaken using computational fluid dynamics (CFD). Simulation results have been compared with carefully prepared experimental samples of microfibrous materials. The experiments involved 14 wt.% ZnO/SiO2 at an operating temperature of 400 °C and a challenge gas consisting of 0.5 vol. % of H2S in H2 and were used to validate the CFD models (both geometric and species transport). These results show that CFD predictions of chemical conversion of H2S are within 10–15% of the experimentally measured values. The effects of residence time and dilution with void on the chemical conversion have been studied. Different microfibrous materials were modeled to study the effect of fiber diameter and fiber loading on the chemical conversion and pressure drop. It is observed that the dilution with void has a negative effect on the conversion; however, the addition of fibers not only compensated for the negative effect of dilution but also increased the reaction rate. The main goal of this study is to use CFD as a tool to design new materials with enhanced reactivity and reduced pressure drop. Our work suggests that new materials with enhanced chemical reactivity for a given pressure drop should be designed with fewer, larger diameter fibers. Our results show that the logs of reduction of H2S per pressure drop increased by a factor of six for the material with 8 μm diameter fibers with 3% volume fraction relative to a packed bed with same catalyst loading.

Simulating Analysis for Small Break LOCA Test Facilities by Applying the Volume Scaling With Reduced Pressure and Reduced Height

2001 ◽  
Author(s):  
S. K. Moussavian ◽  
M. A. Salehi
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Test Facility ◽  
Integral Test ◽  
Reduced Pressure ◽  
Simple Loop ◽  
Loss Of Coolant Accident ◽  
Reduced Height ◽  
Simulating Analysis ◽  
Loss Of Coolant

Abstract In this paper first we briefly define the different scaling schemes and scaling logic in which we use these schemes to simulate the Small-Break Loss Of Coolant Accident (SB-LOCA) in test facilities. The simple loop of the test facility is considered and the mass, momentum and energy conservation equations are used for the derivation of the scaling model. The variations of mass flow rate, pressure drop and the void fraction in the loop as functions of the time scale or the inventories are obtained. Finally, the calculated results from the simulating schemes are compared with the experimental data previously obtained in an integral test facility.

Reduced Pressure Drop in Viscoelastic Polydimethylsiloxane Wall Channels

Langmuir ◽  
2021 ◽  
Author(s):  
A-Reum Kim ◽  
Sushanta K. Mitra ◽  
Boxin Zhao
Keyword(s):  
Pressure Drop ◽  
Reduced Pressure

A General Frictional Pressure Drop Correlation for Condensation in Microfin Tubes

2017 ◽  
Author(s):  
Zhichuan Sun ◽  
Wei Li
Keyword(s):  
Pressure Drop ◽  
Reduced Pressure ◽  
Error Band ◽  
Frictional Pressure Drop ◽  
New Correlation ◽  
Data Points ◽  
Fin Tubes ◽  
Microfin Tubes ◽  
Experimental Pressure ◽  
Good Agreement

Experimental pressure drop data of condensation from the previous literature were collected to develop a general frictional pressure drop correlation for horizontal micro-fin tubes. The collected database contained 481 data points, covering nine working fluids at average saturated condensing temperatures ranging between 14 and 65°C, with mass velocities ranging from 50 to 800 kg/m2s, and average vapor qualities from 0.11 to 0.91. The hydraulic diameter of micro-fin tubes varied from 2.16 to 5.67 mm and was employed in the calculation of Reynolds number. The Fanning frictional factor was calculated by adopting the Churchill model with the empirically fitted relative roughness. Four existing pressure drop correlations developed for micro-fin tubes were evaluated by the database for condensation in micro-fin tubes. The correlation proposed by Cavallini et al. was the best prediction model among them, predicting 85.6% of the collected data points within the 30% error band. In addition, a new correlation based on the Martnelli parameter Xtt modified by incorporating the reduced pressure was proposed to predict the present database, which showed a good agreement.

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