Two-dimensional finite element modeling procedures are addressed to predict the residual stresses for multipass welds. A generalized plane strain model with a five-pass weld in a plate and an axisymmetric model with a six-pass girth weld in a pipe are considered. Element rebirth and pass-lumping techniques are employed in both models. The combined heat input using surface and body flux componen...

fridges are used in various industries, and heat exchanger is one of the main components of these systems; therefore, efficiency analysis of these systems is very important. in many fridges, frost over the heat exchanger tubes or pipes affects the system operation and reduces heat transfer between the refrigerant and ambient, so defrosting systems are usually used to enhance heat transfer. desi...

Abstract---In this work a pseudo-three-dimensional analytical model is developed for the steady incompressible vapor and liquid flow in an asymmetrical disk-shaped heat pipe. The hydrodynamic coupling of the vapor and liquid flow, the gravitational effects and the effects of non-Darcian transport through the porous wick are incorporated in the model, and the variations in upper and lower liquid...

An extensive product range is mandatory to be a key player in the pipe insulation market. The polyurethane preinsulated pipe producers are responding to global opportunities by diversifying their activities into industrial, marine, oil and gas applications. Moreover, the requirements for traditional district heating preinsulated pipes including initial thermal conductivity and its ageing perfor...

1. ABSTRACT We are developing innovative heat pipes based on Nano-Structured Titania (NST) with a potential for high heat carrying capacity and high thermal conductivity. These heat pipes have a flat geometry as opposed to a cylindrical geometry found in conventional heat pipes. The flatness will enable a good contact with microprocessor chips and thus reduce the thermal contact resistance. We ...

3 PREFACE 4 ACKNOWLEDGEMENTS 5 PUBLICATIONS 6 ABBREVIATIONS AND NOMENCLATURE 7 TABLE OF CONTENTS 10 INDEX OF FIGURES 11 INDEX OF TABLES 14 1 INTRODUCTION – BASIC CONCEPTS 15 1.1 GROUND SOURCE HEAT PUMPS 15 1.2 THERMAL PROCESSES IN THE GROUND 18 1.3 SECONDARY WORKING FLUID FLOW 20 1.3.1 Hydrodynamic considerations 21 1.3.2 Thermal considerations 21 1.4 THERMAL RESISTANCES IN BHES 23 1.5 ...

A heat pipe is a self-contained structure which achieves very high thermal conductance by means of two-phase fluid flow with capillary circulation. A quantitative engineering theory for the design and performance analysis of heat pipes is given. iynC QUALITY INSPECTED 3 Aoe*8sloQ For HTIS GRAAI DTIC TAB Unannounced JuatLfloatloa. ■^ 0 a

ARTICLE INFO Cooling of electronics component is one of the major challenges faced by thermal engineers. In recent years, a significant increase in microprocessor power dissipation coupled with CPU size has resulted in an increase in heat fluxes. Microprocessor heat fluxes have also increased for many commercial applications. Therefore, thermal management is becoming one of most challenging iss...