questions on methods of heat transfer

... optimization; Heat transfer law 1 Introduction Recently, the intensive consumption of energy and the exhaustion of resources lead to the rising costs for energy Hence, from the economic perspective, ... profit rate and efficiency of the irreversible Carnot heat engine based on the radiative heat transfer law The relationships between the profit rate and efficiency of the irreversible Carnot heat ... (38) where σ is the rate of entropy production of the generalized irreversible heat engine cycle When maximizing the profit under this condition, minimization of the losses of exergy can be achieved

Ngày tải lên: 09/09/2015, 10:32

... International Energy and Environment Foundation - All rights reserved Keywords: Fins; Heat transfer; Natural convection; Heat sink, CFD 1 Introduction Natural convection heat transfer from these heat ... heat transfer analysis was carried off three governor equations (conservation of mass, conservation of momentum and conservation of energy) Nakhi and Ali [13] focused on the analytical study of ... variation in the fluid, then it is called natural convection [2] The convective heat transfer rate depends on the properties of the fluid flow [3] Experimental works on natural convection heat transfer

Ngày tải lên: 20/11/2015, 14:04

... vacuum condition inside the thermosyphon The measured parameters were: heat input of the evaporator sectionQin, heat output of the condenser sectionQc, temperature of inlet and outlet of the coolant ... experimental results of previous works 2 The condensation and evaporation heat transfer coefficient increases as filling ratio increases 3 Maximum of the heat transfer coefficient of condenser is at ... (3b) The experimental heat transfer coefficient of laminar film in condenser of a heat pipe is: ) c c c T T A Q h − And the analytical correlation of the condenser section in reference [2] is

Ngày tải lên: 09/09/2015, 10:32

... incorporation of an additional empirically determined heat loss term, which is a function of the distance from the wall and Reynolds number, to the conventional heat loss from hot-wire equation to ... boundary condition, their respective hot-wire correction curve exhibit completely opposite trend for non-conducting wall of adiabatic thermal boundary condition Chew et al showed that for the non-conducting ... distortion of velocity field by the wall and consequent alteration of the heat transfer characteristics of the hot wire such that there is on overall larger heat loss to the flow On the other

Ngày tải lên: 16/09/2015, 17:14

... conduction heat transfer condition WOS without conduction heat transfer condition y+ dimensionless distance Y distance from wall yB distance from point B to wall ε rate of dissipation of turbulence ... 8.2.5.1 Effect of inlet Reynolds number 8.2.5.2 Effect of gravity direction on heat transfer 8.3 Conclusions CHAPTER 9: CONCLUSIONS 148 9.1 General conclusions 9.2 Major contributions to knowledge ... conditions 132 Figure 8.4: Effect of wall materials on heat transfer for both WOS and WS conditions 133 Figure 8.5: Effect of reflection coefficient on heat transfer for both WOS and WS conditions

Ngày tải lên: 17/09/2015, 17:19

... velocity (m/s) hw convection heat transfer coefficient (W/m2K) Cp specific heat of air (J/kg K) Ac area of absorber plate surface (m2) i position of the thermocouple connected of 1–4 DT temperature ... forced convection[22,23], extend-ing heat transfer area [24,25] and increasing air turbulence [26,27] Experimental Thermal analysis and uncertainty Heat transfer coefficients The convective heat transfer ... cover helps to decrease convection heat losses In the presence of fins, this exchange is effective along the entire length of the channel Figs.6a,6b,7a and7b show the variation of the thermal efficiency

Ngày tải lên: 13/01/2020, 11:50

... Inactivation of PSII by heat stress is related to damage of the donor side, the reac-tion center and the acceptor side of the photosystem’s electronic transport chain [27] The inhibition of PSII ... including the donor side, reac-tion center and acceptor side of PSII Discussion Methods of investigating heat injury in grapevines Fv/Fm Based on this result, the heat injury of ‘Jingxiu’, ‘Reisling’ ... was observed in the critical values of ‘Jingxiu’, ‘Riesling’ and spine grape: heat injury of grapevines The comparison of investigation methods for heat injury of grapevines under Tc and OJIP test

Ngày tải lên: 27/05/2020, 02:07

... Insulation S E Trang 5SOLUTION By conservation of energy, the heat loss through the two specimens must equal the power dissipation of the heater Therefore the heat transfer through one of the ... one dimensional, steady state conduction (from Equation (1.3)) Converting the thermal conductivity in the English system of units using the conversion factor found on the inside front cover of ... heat transfer by convection (Equation (1.10)) from the outer surface must be the same as the rate of heat transfer by conduction through the glass • This value for the convective heat transfer

Ngày tải lên: 21/08/2020, 09:48

... rate of heat transfer by convection (Equation (1.10)) from the outer surface must be the same as the rate of heat transfer by conduction through the glass  This value for the convective heat transfer ... conductivity of the material at the mean temperature in W/(m K)  One dimensional, steady state conduction  No heat loss from the edges of the apparatus SKETCH SOLUTION By conservation of ... conservation of energy require that the heat gain of the probe by radiation if equal to the heat lost by convection The rate of heat transfer by convection is given by Equation (1.10) q c = h c A T =

Ngày tải lên: 21/08/2020, 13:29

... 2TABLE OF CONTENTS CANDIDATE’S STATEMENT i ACKNOWLEDGEMENTS ii ABSTRACT iii LIST OF ABBREVIATIONS iv TABLE OF CONTENTS v PART A: INTRODUCTION 1 1 Rationale 1 2 Objectives of the ... main part and conclusion - The introduction includes the rationale, aims of the study, scope of the study, methodology and design of the study as well - The main part consists of four chapters ... such as the concept of morpheme, the meaning, the function of vocabulary items in a sentence, the sequence of use … 1.2.1 According to the concept of morpheme: Based on this criterion, words are

Ngày tải lên: 30/09/2020, 12:18

... parameters identification, Proper Orthogonal Decomposition (POD), Radial Basis Function (RBF). 1 INTRODUCTION In direct heat transfer analysis, distribution of temperature within a conducting do-main ... numerical model for estimation of heat transfer parame-ters, e.g thermal conductivity and convective coefficient, in two-dimensional solid bodies under steady-state conduction This inverse problem ... the influence of noise in measured temper-ature data, improving the stability of inverse heat transfer analysis Consequently, the benefit of the employment of POD in inverse heat transfer problems

Ngày tải lên: 28/06/2021, 11:18

... free convective flow of viscous fluids along a vertical plate in presence of variable suction or injection under different physical situations The phenomenon of free convection and mass transfer ... friction and the rate of heat transfer are discussed with the help of figures and tables Copyright © 2010 International Energy and Environment Foundation - All rights reserved Keywords: Heat transfer, ... -6.4648 4.4 Rate of heat transfer The rate of heat transfer at the wall i.e the heat flux in terms of Nusselt number N u for different values of α and K p are entered in Table 2 The heat flux at

Ngày tải lên: 05/09/2013, 14:58

... enhancement ofheat transfer due to conduction under-b Heat transfer enhancement studies via convection/mixed heat transfer mode (91 observations) Strongevidence of heat transfer enhancement by nanofluids ... category of nanofluids The final sec-tion contains the main conclusions reached by the cur-rent review Characteristics of nanofluids This section epitomizes the most common nanofluid preparation methods ... of a large amount of publications regardingthe anomalous heat transfer modes of nanofluids The application of nanofluids as coolants is a novel practise with no established physical foundations

Ngày tải lên: 21/06/2014, 03:20

... the consideration of heat exchange by combined convection and radiation The external irreversibility effects due to finite rate heat transfer as well as the effects of internal dissipations have ... optimal expansion of a heated working fluid with convective radiative heat transfer [7] and to investigate the effects of variable specific heat ratio of working fluid on the performance of an irreversible ... mechanisms, which are Newtonian and radiative heat transfers and given as R L Equation (1) can be written as where A is the heat transfer area, h is the convection heat transfer coefficient between

Ngày tải lên: 05/09/2013, 15:28

... of heat transfer laws on relation between ecological function and efficiency Figure 8.The effects of heat transfer laws on relation between entropy generation rate and efficiency Trang 106 Conclusion ... performance of irreversible Stirling , Ericsson and Brayton heat-engines [34, 35] In general, heat transfer is not necessarily linear Heat transfer law has a strong effect on the performance of endoreversible ... function (E) versus efficiency (η ) curves are parabolic-like ones, and the entropy generation rate (σ ) is a monotonically decreasing function of efficiency (η ) 4.2 Effects of heat transfer law on

Ngày tải lên: 05/09/2013, 15:28

... Classification of question 12 2.2.1 Yes-No questions 12 2.2.2 Wh-questions 13 2.2.3 Alternative questions 13 3 Intonation 14 3.1 What is intonation ? 14 3.2.The roles of intonation 16 3.3 Intonation ... overview of English sentence, question, roles of intonation, difference between tonal language and intonation language, functions of intonation and some major intonation features Chapter 2 is intonation ... intonation in subclasses of question will be mentioned in this chapter As mentioned above, questions are classified into three subclasses: Yes-No questions, Wh-questions and Alternative questions

Ngày tải lên: 11/12/2013, 23:52

... configuration of matter and force fields atone time, the configurations at all later times For example, Newton’s laws achieve-of motion and gravitational attraction can predict the positions achieve-of ... meeting of the National Research Council’s (NRC’s) Board on Physics and Astronomy (BPA) featured a stimulating science session onthe frontiers of research at the intersection of physics and astronomy ... appears to be causing the expan- sion of the universe to accelerate, additional dimensions beyond the usual three of space and one of time, strong-field gravitational physics, very- high-energy

Ngày tải lên: 24/04/2014, 17:17

... effect of a gap in the inclined rib on the heat transfer and fluid flow characteristics of heated surface. A rectangular duct of aspect ratio of 5.83 has been used to conduct experiments on one ... Distribution of total turbulence intensity at a distance of 12.0 mm from downstream face of the rib 5. Conclusion In the present investigation study the effect of gap width on the heat transfer ... roughness on two opposite walls with all four walls being heated. However in the case of solar air heaters, the roughness elements have to be considered only on one wall, which is the only heated...

Ngày tải lên: 05/09/2013, 16:10

... follows: rate of heat conduction rate of heat conduction into control volume out of control volume +=+ (2.1) rate of heat generation rate of energy storage inside control volume inside control volume We ... part. CONTENTS Chapter 1 Basic Modes of Heat Transfer 2 1.1 The Relation of Heat Transfer to Thermodynamics 3 1.2 Dimensions and Units 7 1.3 Heat Conduction 9 1.4 Convection 17 1.5 Radiation 21 1.6 ... 228 Chapter 4 Analysis of Convection Heat Transfer 230 4.1 Introduction 231 4.2 Convection Heat Transfer 231 4.3 Boundary Layer Fundamentals 233 4.4 Conservation Equations of Mass, Momentum, and...

Ngày tải lên: 08/04/2014, 11:00

... radiation and convection would not a}ect the peak temperature calculation and the con! clusions of this work[ 2[1[ Interfacial kinetic relations As the consequence of the one!dimensional heat con! duction ... of several micrometers\ therefore\ heat transfer at the center of the laser beam is essentially one!dimensional[ The one! dimensional heat conduction equation for both the solid and the liquid ... considered[ 2[0[ Governin` equations A one!dimensional heat conduction model is used to calculate heating and phase transformation in the target[ The one!dimensional model is appropriate since...

Ngày tải lên: 06/05/2014, 08:55