scholarly journals Experimental Investigation on the Pressure Drop of Air Flows Through Aluminum and Nickel-Chromium Metallic Foams for HVAC Applications

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 172 ◽  
Author(s):  
Stefano Cancellara ◽  
Matteo Greppi ◽  
Matteo Dongellini ◽  
Giampietro Fabbri ◽  
Cesare Biserni ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Metal Foam ◽  
Threshold Value ◽  
Metallic Foams ◽  
Air Velocity ◽  
Nickel Chromium ◽  
Inertia Coefficient ◽  
Flow Pressure ◽  
Industrial Use

In this paper, a series of experimental data about the role of the metal foam thickness on the total air flow pressure drop is presented. The tested metallic foams are based on aluminum and nickel-chromium and they are characterized by a considerable value of porosity (>0.92) and by a number of pores per linear inches (PPI) close to 10. The measures were conducted in a range of air velocity values typical for HVAC fan-coils. Under these conditions, the flow regime into the pores is highly turbulent. It was demonstrated that below a threshold value of the ratio between the thickness of the porous medium (H) and the characteristic dimension of the pores (d), the dispersion of the pressure drop values from a sample to another one can be very high. This behavior can limit the industrial use of these materials. In addition, the results presented in this paper confirm that the pressure drop data obtained under highly turbulent conditions can be conveniently used in order to determine the inertia coefficient, C, of the metal foam.

Flow Patterns and Pressure Drop in Air/Water Two-Phase Flow in Horizontal Helicoidal Pipes

1995 ◽  
Vol 117 (4) ◽  
pp. 720-726 ◽  
Author(s):  
A. Awwad ◽  
R. C. Xin ◽  
Z. F. Dong ◽  
M. A. Ebadian ◽  
H. M. Soliman
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Helix Angle ◽  
Flow Patterns ◽  
Current Data ◽  
Phase Flow ◽  
Air Velocity ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Flow Pressure

An experimental investigation is conducted for air/water two-phase flow in horizontal helicoidal pipes. The helicoidal pipes are constructed of 25.4 mm I.D. Tygon tubing wrapped around cylindrical concrete forms with outside diameters of 62 cm and 124 cm. The helix angles of the helicoidal pipes vary from 1 to 20 deg. The experiments are performed for superficial water velocity in a range of UL = 0.008 ~ 2.2 m/s and for superficial air velocity in a range of UG = 0.2 ~ 50 m/s. The flow patterns are discerned and recorded photographically. The pressure drop of the air/water two-phase flow in the coils is measured and the Lockhart-Martinelli approach is used to analyze the data. The results are presented in the form of frictional pressure drop multipliers versus the Lockhart-Martinelli parameter. It was found that the flow patterns differ greatly from those of the straight pipe, and that the frictional pressure drop multipliers depend on both the Lockhart-Martinelli parameter and the flow rates. The correlation of the frictional pressure drop has been provided based on the current data. Furthermore, it was also found that the helix angle of the helicoidal pipe had almost no effect on the air/water two-phase flow pressure drop in the present experimental ranges.

scholarly journals Mass Flow, Pressure Drop, and Leakage Dependent Modeling and Characterization of Solar Air Collectors

2014 ◽  
Vol 48 ◽  
pp. 250-263 ◽  
Author(s):  
Christian Welz ◽  
Christoph Maurer ◽  
Paolo Di Lauro ◽  
Gerhard Stryi-Hipp ◽  
Michael Hermann
Keyword(s):  
Pressure Drop ◽  
Mass Flow ◽  
Flow Pressure

Assessment of heat transfer and pressure drop of metal foam-pin-fin heat sink

2021 ◽  
Vol 170 ◽  
pp. 107109
Author(s):  
Mohanad A. Alfellag ◽  
Hamdi E. Ahmed ◽  
Mohammed Gh. Jehad ◽  
Marwan Hameed
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Sink ◽  
Metal Foam ◽  
Pin Fin

Evaluation Analysis of Prediction Methods for Two-Phase Flow Pressure Drop in Mini-Channels

2008 ◽  
Author(s):  
Licheng Sun ◽  
Kaichiro Mishima
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Turbulent Region ◽  
Frictional Pressure Drop ◽  
New Correlation ◽  
Mini Channels ◽  
Flow Pressure ◽  
Better Than

2092 data of two-phase flow pressure drop were collected from 18 published papers of which the working fluids include R123, R134a, R22, R236ea, R245fa, R404a, R407C, R410a, R507, CO2, water and air. The hydraulic diameter ranges from 0.506 to 12mm; Relo from 10 to 37000, and Rego from 3 to 4×105. 11 correlations and models for calculating the two-phase frictional pressure drop were evaluated based upon these data. The results show that the accuracy of the Lockhart-Martinelli method, Mishima and Hibiki correlation, Zhang and Mishima correlation and Lee and Mudawar correalion in the laminar region is very close to each other, while the Muller-Steinhagen and Heck correlation is the best among the evaluated correlations in the turbulent region. A modified Chisholm correlation was proposed, which is better than all of the evaluated correlations in the turbulent region and its mean relative error is about 29%. For refrigerants only, the new correlation and Muller-Steinhagen and Heck correlation are very close to each other and give better agreement than the other evaluated correlations.

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