example of heat transfer through radiation

... Trang 1Proceedings of NHTC'01 35th National Heat Transfer Conference Anaheim, California, June 10-12, 2001 NHTC2001-20070 MOLECULAR DYNAMICS SIMULATION OF HEAT TRANSFER AND PHASE CHANGE ... the surface of the target by scaling velocities of atoms in cells on the top surface, and the same amount of heat flux is dissipated from the bottom of the target by scaling velocities of atoms ... the distribution of number density of atoms in space at different times, which demonstrates the variation of solid structure during laser heating At the early stage of laser heating, the crystal

Ngày tải lên: 06/05/2014, 08:55

... In this study the heat transfer coefficient of condenser and evaporator and the heat transfer limits were investigated The analytical heat transfer coefficient and the heat transfer limits and ... 5 shows the experimental data of Noie [10] for heat transfer coefficient of evaporator Figure 5 Heat transfer coefficient of evaporator versus average temperature of evaporator surface for different ... with small fill rates, Heat Recovery Systems,7(4), pp 319-327 [6] Busse, C.A., (1973) Theory of ultimate heat transfer limit of cylindrical heat pipes Int J Heat and Mass Transfer,16, pp 169-186

Ngày tải lên: 09/09/2015, 10:32

... Carnot heat engine of the same heat input, the generalized irreversible Carnot engine can deliver less power and release more heat to the heat sink Hence, the rate of heat flow (QLC) to the heat ... surface areas of high- and low-temperature side heat-exchangers The total heat transfer surface area of the two heat exchangers is taken as a constant , that is T F F And a ratio ( f ) of heat exchanger ... 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

Ngày tải lên: 09/09/2015, 10:32

... water These components of heat transfer are additive but in general not independent 2.2 Heat transfer though porous materials Most of the previous studies on heat transfer through porous materials ... than 10 mm, the effect of radiation and convection in pores is negligible compared to other mechanisms of heat transfer At low temperature, the mechanism of heat transfer through porous materials ... the behavior of heat transfer through porous medium Most thermal insulations are in the form of porous material specifically designed to minimize three fundamental mechanisms of heat transfer process,

Ngày tải lên: 10/09/2015, 15:47

... without the presence of the wall; they attributed this phenomena to the distortion of velocity field by the wall and consequent alteration of the heat transfer characteristics of the hot wire such ... electrically heated sensing probe The variation of heat loss from the thermal element can be interpreted as a measure of the fluid velocity changes There are two fundamentally different types of thermal ... response of the hot wire has enable the faithful measurement of fluctuating velocity in the typical range of frequency and amplitude encountered in a turbulent flow Trang 8C p Specific heat of fluid

Ngày tải lên: 16/09/2015, 17:14

... study of heat transfer and thermal performance with longitudinal fins of solar air heater Foued Chabane a,b,* , Noureddine Moummi a,b, Said Benramache a,c a Mechanical Department, Faculty of Technology, ... 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 difference (C) t time of the during day (h) Vf ... air heater Increasing the area of the ab-sorber plate shape will increase the heat transferred to the fol-lowing air Collector thermal efficiency The efficiency of a solar collector is the ratio of

Ngày tải lên: 13/01/2020, 11:50

... radiative heat transfer equation The negative sign in the rate of heat transfer indicates that the sphere is gaining heat from the surrounding wall Trang 30Note that the rate of heat transfer by radiation ... 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 specimens is q h/2 For ... k D = 20 W/(m K), determine the rate of heat transfer through this section of the wall and the temperatures at the interfaces (a) Rate of heat transfer through the wall (q) (b) Temperature

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 ... SOLUTION 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 specimens is q h/2 For one ... SOLUTION Equilibrium and the 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

Ngày tải lên: 21/08/2020, 13:29

... 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 ... no heat sink/source, the governing equation of steady-state heat transfer in the bodyΩ is written by where T is the temperature and k is the thermal conductivity Without consideration of heat radiation, ... a conducting body, inverse heat transfer analysis is used to determine the thermal properties and/or boundary con-ditions The estimated quantities of inverse heat transfer analysis are very sensitive

Ngày tải lên: 28/06/2021, 11:18

... -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 ... z-components of skin friction at the wall become B m τ 1 1 3 2 4 5 , (50) z sin A A 1 2 π εα τ = − (51) 3.2 Rate of heat transfer The rate of heat transfer i.e heat flux at the wall in terms of Nusselt ... effect of mass transfer on unsteady flow past an accelerated vertical porous plate with suction Das and his co-workers [15] discussed the effect of mass transfer on MHD flow and Trang 2heat transfer

Ngày tải lên: 05/09/2013, 14:58

... 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 ... generalized convective heat transfer law and generalized radiative heat transfer law has been derived [11] The heating load and coefficient of performance of a steady flow endoreversible heat pump cycle ... coefficient of the heat source, α is the absorption coefficient of the heat source and t is the time of absorbing heat process The emittance will be balanced uniformly by absorption for a thin slice of

Ngày tải lên: 05/09/2013, 15:28

... overall heat transfer coefficient and F1 is the heat-transfer surface area of the high- temperature-side heat exchanger , β is the overall heat transfer coefficient and F2 is the heat-transfer ... deriving force of T H −T HC, Q LC is the rate of heat flow from working fluid to the heat sink due to the deriving force of T LC −T L, Q H is rate of heat transfer supplied by the heat source, ... HC>T LC >T L The heat-transfer surface areas (F1 and F2 ) of high- and low-temperature heat exchangers are finite The total heat transfer surface area (F) of the two heat exchangers is assumed

Ngày tải lên: 05/09/2013, 15:28

... objective of this paper is to present the evaluation of condensation and refrigeration heat transfer performances of two types of mirofin tubes namely Tube A and Tube B Trang 22 Literature review Heat ... paper presents the evaluation of heat transfer coefficients for the flow of R22 through internally grooved copper tubes A series of tests were conducted using two types of tubes namely Tube A and ... length of the tube 5 Results and discussions This section covers the presentation of key findings on the heat transfer enhancement through internally grooved copper tubes 5.1 Convection heat transfer

Ngày tải lên: 05/09/2013, 16:10

... equation describes the absorption of heat by the electron system from the laser, the heat diffusion among the electrons, and transfer of heat to the lattice S is the laser heating source term, defined ... model looks at the heating mechanism as consisting of three processes: the absorption of laser energy by the electrons, the transport of energy by the elec-trons, and heating of the lattice by ... phase has a large amount of superheating and that a distinct melt phase develops with duration of the order of nanoseconds. INTRODUCTION In the last few years, the use of femtosecond lasers in

Ngày tải lên: 06/05/2014, 08:53

... procedure of radiation through a circularly shaped, sub-wavelength hole is first outlined, since the results of this calculation are useful to illustrate the mechanisms of radiation transfer enhancement ... Results and discussion Radiation through a small hole of 50 nm in diameter under the illumination of a plane wave of the variation of electric and magnetic fields on the central axis of the hole with ... and in the near-field region of the apertures are obtained through FDTD calculations, which helps to understand the process of light propagation and radiation transfer through these nano-apertures

Ngày tải lên: 06/05/2014, 09:02

... experimental nanofluid heat transfer by Anoop et al [19], which has error of approxi-mately 4% The heat transfer performance of nanofluid flows in circular tube with diameter 4.75 × 10-3m and length of 1.2 ... application of coiled tubes using nanofluids to improve heat transfer performance is investigated Coiled tubes have been known as one of the passive heat transfer enhancement techniques in heat and ... where the mixed mean temperature and total heat transfer of base-fluid and nanofluids are shown It is improves the heat transfer performance The total heat transfer for straight tube increases up

Ngày tải lên: 21/06/2014, 03:20

... 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 ... performance of nanofluidsfor different heat transfer modes Heat transfer characteristics a Heat transfer enhancement studies purely via duction (130 observations)Strong evidence of thermalconductivity ... heat transfer in nanofluids The knowledge of the physical mechan-isms of heat transfer in nanofluids is of vital importance as it will enable the exploitation of their full heat trans-fer potential

Ngày tải lên: 21/06/2014, 03:20

... Specific heat Research work on the specific heat of nanofluids is lim-ited compared to that on thermal conductivity and visc-osity The specific heat of nanofluid depends on the specific heat of base ... quench heat treatment of components Boiling heat transfer characteristics of nanofluids The alteration of thermophysical properties, especially the enhancement of the thermal conductivity, of the ... processes [1] The two phase (boiling) heat transfer is the predominant mode of heat transfer during quenching When the hot metal submerged into the liquid pool, heat transfer is con-trolled by different

Ngày tải lên: 21/06/2014, 04:20

... generally small, concurrent heat transfer by radiation and/or conduction must often be considered However, jet impingement is one of the more effective means of transferring heat by convection and ... (1) Steady-state conditions, (2) Negligible heat transfer through base of transistor, (3) Negligible heat transfer by radiation from surface of transistor ANALYSIS: Subject to the foregoing ... furnace FIND: (a) Rate of heat loss, (b) Annual cost of heat loss SCHEMATIC: ASSUMPTIONS: (1) Steam line operates continuously throughout year, (2) Net radiation transfer is between small

Ngày tải lên: 08/08/2014, 17:20

... Nusselt number (heat transfer coefficient) as a function of roughness and flow parameters in the form of repeated ribs. In order to understand the mechanism of heat transfer through a roughened ... value of turbulent intensity is observed at the relative gap width of 1.0 which is in the line of heat transfer measurements. These results of PIV showed good agreement between the heat transfer ... Investigation of heat transfer and friction for rib- roughened surfaces, Int. Journal of Heat & Mass Transfer 1978; 21: 1143-1156. [4] Webb R.L., Eckert E.R.G. and Goldstein R. J. Heat transfer...

Ngày tải lên: 05/09/2013, 16:10