Results 21 to 30 of about 129 (110)

An Investigation of Refrigerant Void Fraction in Horizontal, Microfin Tubes [PDF]

HVAC&R Research, 2001
A series of experiments to determine void fraction in both condensation and evaporation have been performed in horizontal microfin tubes with refrigerants R134a and R410A. Mass flux varied from 75 kg/m2·s to 700 kg/m2·s and average test section quality varied from 5% to 80%.
D. A. Yashar, M. J. Wilson, H. R. Kopke, D. M. Graham, J. C. Chato, T. A. Newell   +5 more
openaire   +1 more source

Turbulent Forced Convection and Heat Transfer Characteristic in a Circular Tube with Modified‐Twisted Tapes

Journal of Thermodynamics, Volume 2016, Issue 1, 2016., 2016
Heat transfer, pressure loss, and thermal performance assessment in a circular tube heat exchanger with modified‐twisted tapes are reported. The rectangular holes are punched out from the general twisted tape to reduce the pressure loss. The influences of the hole sizes (l/D, LR = 0.30, 0.44, 0.78, and 0.88) and twisted ratios (y/D, TR = 1, 1.5, 2, and
Amnart Boonloi, Withada Jedsadaratanachai, Shripad T. Revankar   +2 more
wiley   +1 more source

CFD Analysis for Heat Transfer Enhancement inside a Circular Tube with Half‐Length Upstream and Half‐Length Downstream Twisted Tape

Journal of Thermodynamics, Volume 2012, Issue 1, 2012., 2012
CFD investigation was carried out to study the heat transfer enhancement characteristics of air flow inside a circular tube with a partially decaying and partly swirl flow. Four combinations of tube with twisted‐tape inserts, the half‐length upstream twisted‐tape condition (HLUTT), the half‐length downstream twisted‐tape condition (HLDTT), the full ...
R. J. Yadav, A. S. Padalkar, Ahmet Z. Sahin   +2 more
wiley   +1 more source

Effect of Tube Expansion on Heat Transfer and Pressure Drop Characteristics During Condensation in Micro-Fin Tubes

Frontiers in Energy Research, 2021
Despite of the large number of research dedicated to condensation heat transfer and pressure drop characteristics in pristine micro-fin tubes, experimental investigation on effects of tube expansion have not been reported in the open literature.
Na Liu, Qian Zhao, Zhixiang Lan
doaj   +1 more source

Modified theoretical models of film condensation in horizontal microfin tubes

International Journal of Heat and Mass Transfer, 2001
The previously proposed theoretical models of film condensation in horizontal microfin tubes have been modified to describe the characteristics of condensing two-phase flow more accurately. The stratified flow regime and the annular flow regime were considered.
WANG, Huasheng, HONDA, Hiroshi, NOZU, Shigeru   +2 more
openaire   +1 more source

In-tube Evaporation Pressure-drop Characteristics of R290 and R404A

Zhileng xuebao, 2006
The experimental results of in-tube evaporation pressure-drop of R290 and R404A in the horizontal smooth tube and the horizontal microfin tube were compared with calculation results by Lockhart & Martinelli pressure-drop correlation,respectively.Moreover,
韩晓霞, 南晓红, 刘咸定
doaj   +2 more sources

Experimental study of convective heat transfer of R32/R134a inside horizontal microfin tubes

Zhileng xuebao, 2003
Experimental study is reported for heat transfer in forced convective boiling of a nonazeotropic mixture of R32/R134a (25%Wt/75%Wt) inside both smooth and microfin tubes with internal spiral grooves.
吴志光, 马虎根, 蔡祖恢
doaj   +2 more sources

Analysis and Optimization of Heat Enhancement for Hydrogen Fueled Micro‐Pin‐Fin Planar Combustor for Thermophotovoltaic Application Using Response Surface Methodology

International Journal of Energy Research, Volume 2025, Issue 1, 2025.
Micro‐thermophotovoltaic (MTPV) systems are a promising technology for converting heat to electricity, but optimizing radiation efficiency and combustor design remains challenging. This study addresses one of the key challenges in designing MTPV systems by enhancing the thermal performance such as radiation heat transfer efficiency of a hydrogen‐fueled
Stephen Bani, Evans K. Quaye, Sydney Lloyd Abbey, Benjamin Addo-Mensah, Douglass Ayittey, Issahaku Sontaa Jakalia, Emmanuel Ogyadu Lartey, Guojun Yu   +7 more
wiley   +1 more source

STUDI EKSPERIMEN PENINGKATAN PERPINDAHAN KALOR FLUIDA NANO CuO /AIR PADA VERTICAL HELICAL MICROFIN TUBE

Rekayasa Mesin
The way to increase heat transfer is to use nanofluids and expand the heat transfer area. This research studied the thermal performance, convection heat change coefficient, and pressure drop in a double pipe heat exchanger experimentally in a vertically ...
Budi Kristiawan, Ilham Khoirudin, Agung Tri Wijayanta, Syamsul Hadi, Hilbran Tama Dida Effendi   +4 more
doaj   +1 more source

Numerical thermal–hydraulic analysis and multiobjective design optimization of a printed circuit heat exchanger with airfoil overlap fin channels

Engineering Reports, Volume 6, Issue 2, February 2024.
The correlation between pressure drop and Reynolds number for both the overlapping and separate airfoils considered in the present study. The pressure drop significantly reduced with the design of the overlapping airfoils. Abstract In this study, we numerically investigated the performance of a printed circuit heat exchanger (PCHE) featuring National ...
Geng‐Chun Kuo, Jun‐Yu Xie, Chih‐Che Chueh   +2 more
wiley   +1 more source