2 examples of heat transfer by radiation

... 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 (1.10) ... 5.67 × 10–8 W/(m2 K4) Trang 32• The surface area of the sphere (A) is 0.1 ft2• The convective transfer coefficient (h c ) = 2.0 Btu/(h ft2 °F) FIND (a) Rate of heat transfer by radiation per unit ... of heat transfer indicates that the sphere is gaining heat from the surrounding wall Trang 30Note that the rate of heat transfer by radiation can be substantially reduced (see Problem 1.23) by

Ngày tải lên: 21/08/2020, 09:48

... 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 (1.10) ... For steady state to exist the rate of heat transfer by convection must equal the rate of heat transfer by radiation Trang 21PROBLEM 1.16 Water at a temperature of 77°C is to be evaporated slowly ... Appendix 2, Table 13 The heat of vaporization of water at 77°C (h fg) = 2317 kJ/kg Trang 22PROBLEM 1.17 The heat transfer rate from hot air by convection at 100°C flowing over one side of a flat

Ngày tải lên: 21/08/2020, 13:29

... considered: 219 elements (272 nodes), 546 elements (622 nodes), 1984 elements (2125 nodes) The “equivalent thermal energy” is defined as d T The value of h is h = 100 W/(m2 K) and that of k is ... considered: 219 elements (272 nodes), 546 elements (622 nodes), 1984 elements (2125 nodes) The “equivalent thermal energy” is defined as d T The value of h is h = 100 W/(m2 K) and that of k is k ... 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,

Ngày tải lên: 28/06/2021, 11:18

... Heat Mass Transfer 2003; 30(2): 241-250 [17] Bhagoria J.L and Sahu M.M Augmentation of heat transfer coefficient by using 900 broken transverse ribs on absorber plate of solar air heater, Renewable ... (g/e) of 1.0 gives the highest value of heat transfer coefficient compared to the other relative gap width To investigate the effect of gap ISSN 2076-2895 (Print), ISSN 2076-2909 (Online) ©2010 ... of the test section whereas the upper walls of entry and exit sections of the duct were made of 12 mm thick plywood The absorber plate is heated from the top by ISSN 2076-2895 (Print), ISSN 2076-2909

Ngày tải lên: 05/09/2013, 16:10

... Apc2 Cdc27 Cdc16 Apc4 Apc5 Apc11 E2 Ub Cdc23 IR C-Box Cdh1 or Cdc20 ? 92.4 http://jbiol.com/content/8/10/92 Matyskiela et al.: Journal of Biology 2009, 8:92 directly to Cdc27 in vitro [26,32], ... subunits Apc1 Cut4 Apc1/Tsg24 Apc2 Apc2 Apc2 Cullin domain Cdc27 Nuc2 Cdc27 TPRs Apc4 Lid1 Apc4 Apc5 Apc5 Apc5 Cdc16 Cut9 Apc6 TPRs - - Apc7 TPRs Cdc23 Cut23 Cdc23 TPRs Apc9 - - Doc1 ... modification of many lysines and the formation of long polyubiquitin chains. Apc1 Doc1 Apc2 Cdc27 Cdc16 Apc4 Apc5 Apc11 E2 Cdc23 IR C-Box Cdh1 or Cdc20 ? Substrate NH 2 Ub NH 2 92.8 http://jbiol.com/content/8/10/92

Ngày tải lên: 06/08/2014, 19:21

... Models of equations The rate of heat transfer to the evaporator section of a thermosyphon can be calculated from the Eq (1) 2 2 /R RI V The rate of heat remove from the condenser section by the ... from [2]: 2 27 / 8 16 / 9 6 / 1 Pr 492 0 1 387 0 825 0 ⎥ ⎥ ⎦ ⎤ ⎢ ⎢ ⎣ ⎡ ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ + + = k hL Nu t (3b) The experimental heat transfer coefficient of laminar film in condenser of a heat pipe ... with correlations of Rohsenow [2] and Imura [3] Figure 5 shows the experimental data of Noie [10] for heat transfer coefficient of evaporator Figure 5 Heat transfer coefficient of evaporator versus

Ngày tải lên: 09/09/2015, 10:32

... (29) yields the optimal temperature ratio and the maximum profit rate of the heat engine ) 1 ( ) 1 ( ) 1 ( ) ( 2 )] 1 ( ) 1 ( [ ) ( ) 1 ( 2 1 2 1 1 2 2 1 2 1 5 0 2 1 1 2 1 1 2 2 5 0 2 1 1 2 ... Eq (25) gives ηπ, which is the finite-time exergoeconomic bound of generalized irreversible Carnot heat engine with Newton’s heat transfer law 1 5 0 2 1 1 2 2 1 5 0 5 0 2 1 1 2 2 1 5 0 2 2 ... Effect of the heat transfer law on the finite-time, exergoeconomic performance of heat engines Energy, 1996, 21(12): p 1127-1134 [12] Chen, L., F Sun, and C Wu, Effect of heat transfer law on

Ngày tải lên: 09/09/2015, 10:32

... parameters 13 2.3 Boundary conditions 19 2.4 Discretization 20 2.5 Second-order upwind scheme 23 2.6 Linearized form of the discrete equation 24 2.7 Under-relaxation 25 2.8 Discretization of the ... momentum equation 25 2.9 Discretization of the continuity equation 26 2.10 Temporal discretization 27 Trang 42.11 Pressure-velocity coupling 292.12 Solution method 32 2.13 Convergence criteria ... 4-25 Critical Y + versus h 0 127 Figure 4-26 Variation of C ui with Re and h 0 for = 1.1 and 1.8 128 Figure 4-27 Variation of C u with Re and h 0 for =1.1 in the low Re range 129 Figure 4-28

Ngày tải lên: 16/09/2015, 17:14

... Model 2.2.1.1 Single slot impinging jet 2.2.1.2 Multiple slot impinging jets 2.2.1.3 Impinging round jets 2.2.1.4 Impinging jet with cross-flow 2.2.2 Studies with LES and DNS approaches 2.2.3 ... 8.2.4.2 Effect of particle diameter 8.2.4.3 Effect of particle material 8.2.5 Effect of inlet conditions 8.2.5.1 Effect of inlet Reynolds number 8.2.5.2 Effect of gravity direction on heat ... material 8.2.3.2 Effect of reflection coefficient on heat transfer 8.2.3.3 Effect of impingement wall temperature 8.2.4 Effect of particle factors on heat transfer 8.2.4.1 Effect of constant

Ngày tải lên: 17/09/2015, 17:19

... plate [20,21] Fig 2 The conventional flat-plate solar air heater has been investigated for heat transfer efficiency improvement by introducing forced convection[22,23], extend-ing heat transfer ... thermohydraulic performance of artificially roughened solar air heaters Renew Energy 2000;20(1):19–36 [27] Yeh HM Theory of baffled solar air heaters Energy 1992;17(7):697–702 [28] McAdams WH Heat transmission ... 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 difference (C) t time of

Ngày tải lên: 13/01/2020, 11:50

... rate of heat transfer by radiation to the tube surface is comparable to that by convection, and theassumption of negligible radiation is inappropriate (2) If heat transfer from the air is by natural ... q and m are achieved with r2 = 0.26 m With increasing r2, q and m decrease from values of 1702 W and 8×10-3 kg/s at r2 = 0.25 m to 0.627 W and 2.9×10-6 kg/s at r2 = 0.30 m COMMENTS: Laminated ... Cylindrical containers of aspect ratio L/D = 1 are seldom used because of floor space constraints Choosing L/D = 2, ∀ = πD3/2 and D = (2∀/π)1/3 = 0.623 m Hence, L = 1.245 m, r1 =0.312m and r2 = 0.337 m

Ngày tải lên: 08/08/2014, 17:20

... 2H)− 2.185] −2 , 1500≤ Re 2H ≤ 2.5×106, (2.25) Trang 8Note that the original Petukhov and Gnielinski correlations are rewrit-ten here in terms of Re 2H rather than Re Dh , where Re Dh = 2Re 2H ... equation is given by the S-A model on as follows:κ2˜2f ν2, Ωij = 12 The model constants are σ ν = 2/3, C b1 = 0.1355, C b2 = 0.6220, κ = 0.4187, C ν1 = 7.10, C w2 = 0.30, C w3 = 2.0 In DES (Spalart ... Re 2H of the modified surface channel flow for consistentcomparison Trang 18Figure 2.2: Effects of Reynolds number on C f and N u2.4.2 Other parameters and flow structure More detailed results of

Ngày tải lên: 10/09/2015, 09:11

... regime as evidenced by the 0.3 0.1 0.2 0.0 0.2 0.1 0.2 0.0 0 24 0 24 0 24 0 24 0 24 48 Colony Halo Halo area/colony area 0 2 4 6 8 10 1214 16 1 10 100 1,000 30 20 10 0 20 10 0 20 10 20 10 0 0 Time ... Trang 1Received 25 Feb 2016 | Accepted 9 Aug 2016 | Published 22 Sep 2016Adaptive radiation by waves of gene transfer leads to fine-scale resource partitioning ... 1228–1231 (2012) 13 Yawata, Y et al Competition-dispersal tradeoff ecologically differentiates recently speciated marine bacterioplankton populations Proc Natl Acad Sci USA 111, 5622–5627 (2014)

Ngày tải lên: 08/11/2022, 15:01

... (m/s) 20 40 60 80 100 20 40 60 80 100 Trang 22PROBLEM 1.20KNOWN: Inner and outer surface temperatures of a wall Inner and outer air temperatures and convection heat transfer coefficients FIND: Heat ... and cost of natural gas FIND: Daily cost of heat loss SCHEMATIC: ASSUMPTIONS: (1) Steady state, (2) One-dimensional conduction, (3) Constant properties ANALYSIS: The rate of heat loss by conduction ... difference across a sheet of rigid T - T dT COMMENTS: (1) Be sure to keep in mind the important distinction between the heat flux (W/m2) and the heat rate (W) (2) The direction of heat flow is from

Ngày tải lên: 20/08/2020, 12:02

... 1.7205 -0.1295 1.3856 -0.1297 1.3367 -0.1298 0.5 3.4317 -0.3382 2.2620 -0.3394 1.9135 -0.3396 1.8632 -0.3398 2.0 7.7599 -1.6834 6.5651 -1.7057 6.3043 -1.7106 6.2722 -1.7112 5.0 22.762 -6.2661 21.947 ... 0.008696 0.005020 0.003889 0.003723 0.2 0.186269 0.181441 0.180830 0.180797 0.5 0.465496 0.461281 0.460627 0.457991 2.0 2.158400 2.145131 2.120497 2.024807 5.0 9.873545 9.354939 9.287622 9.280233 ... )y ] B e B y e 14 5 13 2 2 12 2 1 11 2 2 where 2 1 2 2 2 P R B e r − εα 2 1 m R − εα 2 1 2 2 A A P R m − α ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ + π − + α − + = p e e K R m A R m A A B 2 1 2 1 2 ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ + π − + α

Ngày tải lên: 05/09/2013, 14:58

... Carnot refrigerator with heat transfer law. Proceeding of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering, 2008, 222(E1):55-62. [20] Liu X., Chen L., Wu ... and Environment, 2012, 3(1):19-32. [23] Liu C., Chen L., Sun F. Endoreversible Meletis-Georgiou cycle. Int. J. Energy and Environment, 2012, 3(2):305-322. International Journal of Energy and Environment ... of releasing heat process. The radiation heat transfer coefficient of the hot side is () ( ) 2 2 2 2 TTTTh HHHH R ++= σε (6) With L H T T = θ , L T T 1 = ω , 1 2 T T = γ , C R L L h h = λ , C

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 ... results of irreversible Carnot heat engine with Newtownian heat transfer law [22, 33, 56, 57] If m=1.25, they are the results of irreversible Carnot heat engine [56] with Dulong-Petit heat transfer ... results of irreversible Carnot heat engine with Newtownian heat transfer law [22, 33, 56, 57] If n= −1, they are the results of irreversible Carnot heat engine with linear phenomenological heat transfer

Ngày tải lên: 05/09/2013, 15:28

... 115 ± 21 (4) a 43 ± 3 282 ± 58 (4) 200 ± 26 (6) 168 ± 25 (5) 72 ± 2 532 ± 48 (3) b,c 296 ± 61 (4) c 216 (2) 92 ± 3 546 ± 38 (5) d,e 205 ± 41 (6) d 130 ± 24 (4) e 115 568 (2) 290 (2) 190 (2) Significant ... 0.06 (3) d 102 (2) 92 h of culture Control 0.46 ± 0.14 (3) 7.9 (2) 0.70 ± 0.10 (3) 82 (2) + oxalate 0.33 (2) 10 (2) 0.46 ± 0.12 (3) 92 (2) + oligomycin 0.13 ± 0.07 (3) 8.6 (2) 0.26 ± 0.14 (3) ... (3) b 156 (2) 43 h of culture Control 0.54 ± 0.20 (3) 16 (2) 0.44 ± 0.03 (3)c,d 106 (2) + oxalate 0.22 ± 0.13 (3) 17 (2) 0.18 ± 0.09 (3)c 131 (2) + oligomycin 0.30 ± 0.16 (3) 14 (2) 0.11 ± 0.06

Ngày tải lên: 30/03/2014, 20:20

...
13 T 5 ½22 Specific heat of the liquid phase C liq (J=kg K) 157.194 [22] Electron–lattice coupling factor G (W=m3K) (s, solid liq, liquid) s, 2:0  10 16 ½2 liq, 2:4  10 16 Enthalpy of evaporation ... evaporation Llvat Tb(J=kg) 1.698 10 6 ½22 Enthalpy of fusion Lsl(J=kg) 6:373  10 4 ½22 Molar weight M (kg=kmol) 196.967 [22] Reflection coefficient R 0.36262 [23] Universal gas constant Ru(J=K mol) ... (nm) 18.22 [23] Fermi energy e F (eV) 5.53 [23] Thermal conductivity of the solid phase k s (W=mK) 320:973
0:0111T
2:747 10
5 T 2
4:048  10
9 T 3 ½25 Thermal conductivity of the liquid

Ngày tải lên: 06/05/2014, 08:53

... Coordinates 21 5 3.6* Irregular Boundaries 21 7 3.7 Closing Remarks 22 1 References 22 1 Problems 22 2 Design Problems 22 8 Chapter 4 Analysis of Convection Heat Transfer 23 0 4.1 Introduction 23 1 4 .2 Convection ... separately heat flow paths. R 5 = L 2 0.7k a = 11 > 32 in .2 1 12 in./ft210. 02 Btu/h °F ft2 = 186 * 10 -3 (Btu/h ft 2 °F) -1 R 4 = L 2 0.3k b = 11 > 32 in .2 1 12 in./ft210. 321 1 Btu/h °F ft2 = 8.68 ... 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 Combined Heat Transfer...

Ngày tải lên: 08/04/2014, 11:00