Assessing a parallel baffle splitter, an experimental and numerical study on insertion loss and pressure drop

HVAC systems are composed of different noise sources and paths. The non-attenuated propagation of noise through the system has detrimental effects on acoustic comfort of people inside the premises. To mitigate the propagated noise, parallel baffle splitters are used which reduce the transmitted noise through acoustic coatings. Different methods have been developed to predict the insertion loss of those elements, however, if the input data is not well known these models can lead to deviated results. On the other hand, the use of splitter in HVAC systems produces pressure drop which can damage the equipment used if that is not well predicted. Different models are available in the literature, which relates dimensional features and design velocity to estimate the pressure drop coefficient. However, models can give overestimated results. In this work an experimental rig was implemented to assess a splitter installed inside of a test duct. Measurements were performed to estimate insertion loss and pressure drop coefficient, following the guidelines exposed on the ISO 7235 standard. The results were compared with analytic methods. Finally, a numerical method analysis of the test rig was performed, showing the correlation between these results and the experimental data.

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Assessing a parallel baffle splitter, an experimental and numerical study on insertion loss and pressure drop

INTER-NOISE and NOISE-CON Congress and Conference Proceedings ◽

10.3397/in-2021-1336 ◽

2021 ◽

Vol 263 (6) ◽

pp. 194-205

Author(s):

Juan Pablo Escudero ◽

Hctor Fuentes

Keyword(s):

Pressure Drop ◽

Insertion Loss ◽

Numerical Study ◽

Hvac Systems ◽

Mechanical Equipment ◽

Noise Sources ◽

Acoustic Comfort ◽

Design Velocity ◽

Method Analysis ◽

Experimental Rig

HVAC systems are composed of different noise sources and paths. The non-attenuated propagation of noise through the system has detrimental effects on acoustic comfort of people inside the premises. In order to mitigate the propagated noise, classic parallel baffe splitters are used to reduce the transmitted noise through acoustic coatings. Different methods have been developed to predict the insertion loss of those elements, however, if the input data is not well known these models can lead to deviated results. Additionally, the use of splitters in HVAC systems produces pressure drop which can damage the installed mechanical equipment if that is not well predicted. Currently, the models that estimate pressure drop relate dimensional features and design velocity. However, these models can give overestimated results. In this work an experimental rig was implemented to assess a splitter installed inside of a test duct. Measurements were performed to estimate insertion loss and pressure drop coeffcient, following the guidelines exposed on the ISO 7235 standard. The results were compared with analytical methods. Finally, a numerical method analysis of the test rig was performed, showing the correlation between these results and the experimental data.

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Numerical Study of Thermal-Hydraulic Performance of a New Spiral Z-Type PCHE for Supercritical CO2 Brayton Cycle

Energies ◽

10.3390/en14154417 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4417

Author(s):

Tingting Xu ◽

Hongxia Zhao ◽

Miao Wang ◽

Jianhui Qi

Keyword(s):

Heat Transfer ◽

Pressure Drop ◽

Pressure Loss ◽

Numerical Study ◽

Hydraulic Performance ◽

Optimal Structure ◽

Original Structure ◽

Brayton Cycle ◽

Compact Structure ◽

Spiral Angle

Printed circuit heat exchangers (PCHEs) have the characteristics of high temperature and high pressure resistance, as well as compact structure, so they are widely used in the supercritical carbon dioxide (S-CO2) Brayton cycle. In order to fully study the heat transfer process of the Z-type PCHE, a numerical model of traditional Z-type PCHE was established and the accuracy of the model was verified. On this basis, a new type of spiral PCHE (S-ZPCHE) is proposed in this paper. The segmental design method was used to compare the pressure changes under 5 different spiral angles, and it was found that increasing the spiral angle θ of the spiral structure will reduce the pressure drop of the fluid. The effects of different spiral angles on the thermal-hydraulic performance of S-ZPCHE were compared. The results show that the pressure loss of fluid is greatly reduced, while the heat transfer performance is slightly reduced, and it was concluded that the spiral angle of 20° is optimal. The local fluid flow states of the original structure and the optimal structure were compared to analyze the reason for the pressure drop reduction effect of the optimal structure. Finally, the performance of the optimal structure was analyzed under variable working conditions. The results show that the effect of reducing pressure loss of the new S-ZPCHE is more obvious in the low Reynolds number region.

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Numerical study on pressure drop factor in the vent-cap of CDQ shaft

Journal of Thermal Science ◽

10.1007/s11630-008-0069-y ◽

2008 ◽

Vol 17 (1) ◽

pp. 69-76 ◽

Cited By ~ 2

Author(s):

Bo Song ◽

Yanhui Feng ◽

Xinxin Zhang

Keyword(s):

Pressure Drop ◽

Numerical Study

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A Numerical Study of Fluid Structure Interaction of a Flexible Submerged Cylinder Mounted on an Experimental Rig

Volume 7: Ocean Engineering ◽

10.1115/omae2015-42219 ◽

2015 ◽

Author(s):

Erkan Cakir ◽

Ayhan Akinturk ◽

Alejandro Allievi

Keyword(s):

Numerical Study ◽

Coupled Analysis ◽

Mapping Algorithms ◽

Automatic Mapping ◽

Structural Responses ◽

Submerged Cylinder ◽

Physics Model ◽

System Coupling ◽

Force Data ◽

Experimental Rig

The aim of the study is to investigate VIV effects, not only on a test cylinder but also on the experimental rig being towed under water at a prescribed depth and operating speeds. For this purpose, a numerical Multi-Physics model was created using one way coupled analysis simultaneously between the Mechanical and Fluent solvers of ANSYS software package. A system coupling was developed in order to communicate force data alternately between the solvers with the help of automatic mapping algorithms within millesimal time periods of a second. Numerical investigation into the dynamic characteristics of pressure and velocity fields for turbulent viscous fluid flow along with structural responses of the system, stressed the significance of time and space scales for convergence and accuracy of our Finite Volume (FV) CFD calculations.

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Numerical study on heat transfer and pressure drop characteristics of R410A condensation in horizontal circular mini/micro-tubes

The Canadian Journal of Chemical Engineering ◽

10.1002/cjce.22554 ◽

2016 ◽

Vol 94 (9) ◽

pp. 1809-1819 ◽

Cited By ~ 18

Author(s):

Jingzhi Zhang ◽

Wei Li

Keyword(s):

Heat Transfer ◽

Pressure Drop ◽

Numerical Study

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Numerical study on pressure drop and heat transfer for designing sodium-to-air heat exchanger tube banks on advanced sodium-cooled fast reactor

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2012.08.003 ◽

2013 ◽

Vol 254 ◽

pp. 5-15 ◽

Cited By ~ 10

Author(s):

Hie-Chan Kang ◽

Jae-Hyuk Eoh ◽

Jae-Eun Cha ◽

Seong-O. Kim

Keyword(s):

Heat Transfer ◽

Heat Exchanger ◽

Pressure Drop ◽

Fast Reactor ◽

Numerical Study ◽

Heat Exchanger Tube ◽

Tube Banks ◽

Exchanger Tube

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Numerical Study of Heat Transfer and Pressure Drop Characteristics in Twisted Rectangular Tube

Applied Physics ◽

10.12677/app.2021.112012 ◽

2021 ◽

Vol 11 (02) ◽

pp. 95-107

Author(s):

秋明葛

Keyword(s):

Heat Transfer ◽

Pressure Drop ◽

Numerical Study ◽

Rectangular Tube

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Numerical study of the pressure drop phenomena in wound woven wire matrix of a Stirling regenerator

Energy Conversion and Management ◽

10.1016/j.enconman.2012.10.014 ◽

2013 ◽

Vol 67 ◽

pp. 57-65 ◽

Cited By ~ 52

Author(s):

S.C. Costa ◽

Harritz Barrutia ◽

Jon Ander Esnaola ◽

Mustafa Tutar

Keyword(s):

Pressure Drop ◽

Numerical Study

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Temperature and Velocity Effects on Mass and Momentum Transport in Spacer-Filled Channels for Reverse Electrodialysis: A Numerical Study

Energies ◽

10.3390/en11082028 ◽

2018 ◽

Vol 11 (8) ◽

pp. 2028 ◽

Cited By ~ 5

Author(s):

Zohreh Jalili ◽

Jon Pharoah ◽

Odne Stokke Burheim ◽

Kristian Einarsrud

Keyword(s):

Mass Transfer ◽

Pressure Drop ◽

Concentration Polarization ◽

Numerical Study ◽

Membrane Surface ◽

Lower Pressure ◽

Low Flow ◽

Fluid Temperature ◽

Reverse Electrodialysis ◽

Flow Velocities

Concentration polarization is one of the main challenges of membrane-based processes such as power generation by reverse electrodialysis. Spacers in the compartments can enhance mass transfer by reducing concentration polarization. Active spacers increase the available membrane surface area, thus avoiding the shadow effect introduced by inactive spacers. Optimizing the spacer-filled channels is crucial for improving mass transfer while maintaining reasonable pressure losses. The main objective of this work was to develop a numerical model based upon the Navier–Stokes and Nernst–Planck equations in OpenFOAM, for detailed investigation of mass transfer efficiency and pressure drop. The model is utilized in different spacer-filled geometries for varying Reynolds numbers, spacer conductivity and fluid temperature. Triangular corrugations are found to be the optimum geometry, particularly at low flow velocities. Cylindrical corrugations are better at high flow velocities due to lower pressure drop. Enhanced mass transfer and lower pressure drop by elevating temperature is demonstrated.

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