BULETINUL INSTITUTULUI POLITEHNIC DIN IAŞI

More documents

Recommendations

Info

122 Petru Cârlescu et al air malt bed a b air inlet Fig. 1 – Geometry dryer: a – geometry; b – meshing. Processing the initial stage to impose conditions and calculation is performed in software FLUENT. The conditions chosen to study the effects of temperature and air flow on conditions within a bed of malt are presented in Table 2. Table 2 Initial conditions W – initial moisture content,of the malt, % T – initial temperature of the malt, º C v – velocity of the air, m/s 49 21 1 The physical properties of the system investigated Specific heat of air c a – J/kg º C 1017 Specific heat of liquid water c w – J/kg º C 4187 Specific heat of malt c s - J/kg º C 2008 Density of air ρ a – kg/m 3 1.169 Density of malt ρ s – kg/m 3 639.2 Temperature and humidity content in the input region are introduced as five order polynomial functions of time. Function of temperature is introduced in UDF code in Kelvin as follows −20 5 −16 4 −12 3 −8 2 ( ) = 10 −6⋅ 10 + 9⋅ 10 + 5⋅10 f T τ τ τ + 0.0012τ + 303.22, τ + (13) where: τ – drying time between 0...25200 s. The UDF is introduced as a function of humidity content X kg vapor/kg dry air depending on time. −23 5 −18 4 −14 3 −10 2 ( ) 210 10 210 10 f X = ⋅ τ − τ + ⋅ τ − τ + + ⋅ + −7 4 10 τ 0.0101, (14)
Bul. Inst. Polit. Iaşi, t. LVIII (LXII), f. 3, 2012 123 where: τ – drying time between 0...25200 s. Laminar solver is chosen because the dryer inlet air velocity is small. Processing is performed on a TYAN graphics station dual processor Intel Xeon Six Core 3.33 GHz, 32 GB DDR3 RAM and two Fermi Tesla C2050 cards, and a drying period of 7 hours for which they were made functions of temperature and moisture introduced initially during the calculation of the simulation lasted 15 minutes. Post-processing. The solver produces a map of the distribution of all the variables throughout the domain. This result must be processed so that it can be easily reported, visualized and analyzed. This is the main purpose of the postprocessing task, which is essential for comprehensive evaluation of the simulation. Usual outcomes of post-processing for visualization are temperature and velocity maps, plots of other scalar variables and animations. The postprocessor can also give information about the instantaneous value of all variables at certain positions in the domain, and can perform balances and numerical calculations. Simulation describes the temperature distribution in the malt bed. Temperature transducers can be placed at different points in this bed, but can not be so numerous that to draw a precise temperature profile in both horizontal and vertical section of the malt bed. However the presences of these transducers are needed to calibrate temperature simulations for some initial parameters kept constant in the CFD simulation. Image of Fig. 2 shows the evolution of air temperature at the inlet of the dryer for a period of 25200 sec. equivalent of 7 hours. Fig. 2 – Evolution of air temperature during the drying process. Fig. 3 shows the temperature distribution and evolution in the first layer of malt into contact with hot air, and in Fig. 4 the temperature profile on the exit surface of malt layer at the beginning and the end of drying. Fig. 5 shows the temperature profile and evolution in cross section dryer through of malt bed at the beginning and end of drying.
Page 1:
BULETINUL INSTITUTULUI POLITEHNIC D
Page 5:
Page 8 and 9:
PETRU CÂRLESCU, VASILE DOBRE, IOAN
Page 10 and 11:
2 Niooleta Negoescu continue telle
Page 12 and 13:
4 Niooleta Negoescu min{ μ( Tu , T
Page 14 and 15:
6 Niooleta Negoescu Observation 8.
Page 16 and 17:
8 Ion Crăciun with large molecules
Page 18 and 19:
10 Ion Crăciun ∂ ∂ ∂ ∂ ∇
Page 20 and 21:
12 Ion Crăciun ⎧σ ji = ( μ+ α
Page 22 and 23:
14 Ion Crăciun If we introduce the
Page 24 and 25:
16 Ion Crăciun where the scalar La
Page 26 and 27:
18 Ion Crăciun and 0 0 0 2 2 ⎧
Page 28 and 29:
20 Ion Crăciun Ψ r Having assumed
Page 30 and 31:
22 Ion Crăciun Ignaczak, J., Tenso
Page 33 and 34:
Page 35 and 36:
Bul. Inst. Polit. Iaşi, t. LVIII (
Page 37 and 38:
Page 39 and 40:
Page 41:
Page 44 and 45:
36 Radu Ibănescu and Cătălin Ung
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
44 Petronela Paraschiv case of biom
Page 54 and 55:
46 Petronela Paraschiv calculation
Page 56 and 57:
48 Petronela Paraschiv interpolate
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Page 67 and 68:
Page 69 and 70:
Page 71 and 72:
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80: Bul. Inst. Polit. Iaşi, t. LVIII (
Page 85: Bul. Inst. Polit. Iaşi, t. LVIII (
Page 88 and 89: 80 Gelu Coman and Valeriu Damian ma
Page 90 and 91: 82 Gelu Coman and Valeriu Damian h
Page 92 and 93: 84 Gelu Coman and Valeriu Damian Th
Page 94 and 95: 86 Gelu Coman and Valeriu Damian iv
Page 96 and 97: 88 Florin Popa et al. In this figur
Page 98 and 99: 90 Florin Popa et al. the notations
Page 100 and 101: 92 Florin Popa et al. Δ = 0 and C
Page 103 and 104: BULETINUL INSTITUTULUI POLITEHNIC D
Page 111: Bul. Inst. Polit. Iaşi, t. LVIII (
Page 114 and 115: 106 Vlad Marţian et al there is al
Page 116 and 117: 108 Vlad Marţian et al that all th
Page 118 and 119: 110 Vlad Marţian et al The battery
Page 120 and 121: 112 Vlad Marţian et al Current Int
Page 122 and 123: 114 Vlad Marţian et al Another fac
Page 124 and 125: 116 Vlad Marţian et al În concluz
Page 126 and 127: 118 Petru Cârlescu et al indicate
Page 128 and 129: 120 Petru Cârlescu et al hs p dT d
Page 132 and 133: 124 Petru Cârlescu et al a b Fig.
Page 134: 126 Petru Cârlescu et al Iguaz A.,
show all

BULETINUL INSTITUTULUI POLITEHNIC DIN IAŞI

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?