Abonnement à la biblothèque: Guest
Page d'accueil ICHMT DL Année en cours Archives Comité de direction Centre international pour le transfert de chaleur et de masse

Compound Heat Transfer Enhancement - Performance Characteristics of Some "Rough Surfaces" with Twisted Tape Inserts

DOI: 10.1615/ICHMT.2004.IntThermSciSemin.1240
pages 975-982

Ventsislav D. Zimparov
Gabrovo Technical University, 4 Hadji Dimitar Strasse, 5300 Gabrovo, Bulgaria

Plamen J. Penchev
Gabrovo Technical University, 4, H. Dimitar Str., 5300 Gabrovo, Bulgaria


One of the most promising heat transfer enhancement techniques is the compound augmentation method, in which different enhancement techniques are used simultaneously. This study compares the characteristics of some passive compound techniques for single phase flow studied up to now: rough tube (sand-grain roughness) with twisted tape insert; internally grooved rough tube with twisted tape and corrugated tube combined with twisted insert. The performance characteristics of these combinations of "rough" surfaces and twisted tape inserts have been assessed using extended performance evaluation criteria. The goal is to evaluate the influence of the characteristic parameters of the tubes: height-to-diameter ratio e/D, relative pitch p/e, relative helix angle β* and others, and the relative pitch of the twisted tape H/D on the thermodynamic efficiency. The benefit of replacing the smooth tubes in shell-and-tube heat exchangers for different practical applications have been evaluated and the thermodynamic optimum has been defined by the minimization the entropy generation number compared with the relative increase of the heat transfer rate or relative reduction of the heat transfer area.

ICHMT Digital Library

Bow shocks on a jet-like solid body shape. Thermal Sciences 2004, 2004. Pulsed, supersonic fuel jets - their characteristics and potential for improved diesel engine injection. PULSED, SUPERSONIC FUEL JETS - THEIR CHARACTERISTICS AND POTENTIAL FOR IMPROVED DIESEL ENGINE INJECTION
View of engine compartment components (left). Plots of temperature distributions in centreplane, forward of engine (right). CHT-04 - Advances in Computational Heat Transfer III, 2004. Devel... DEVELOPMENT AND CURRENT STATUS OF INDUSTRIAL THERMOFLUIDS CFD ANALYSIS
Pratt & Whitney's F-135 Joint Strike Fighter Engine under test in Florida is a 3600F class jet engine. TURBINE-09, 2009. Turbine airfoil leading edge stagnation aerodynamics and heat transfe... TURBINE AIRFOIL LEADING EDGE STAGNATION AERODYNAMICS AND HEAT TRANSFER - A REVIEW
Refractive index reconstructed field. (a) Second iteration. (b) Fourth iteration. Radiative Transfer - VI, 2010. Theoretical development for refractive index reconstruction from a radiative ... THEORETICAL DEVELOPMENT FOR REFRACTIVE INDEX RECONSTRUCTION FROM A RADIATIVE TRANSFER EQUATION-BASED ALGORITHM
Two inclusion test, four collimated sources. Radiative Transfer - VI, 2010. New developments in frequency domain optical tomography. Part II. Application with a L-BFGS associated to an inexa... NEW DEVELOPMENTS IN FREQUENCY DOMAIN OPTICAL TOMOGRAPHY. PART II. APPLICATION WITH A L-BFGS ASSOCIATED TO AN INEXACT LINE SEARCH