SOLVE - Heat transfer Lab - Heat Transfer Coefficient of a Composite Wall

To determine the convective heat transfer coefficient and the rate of heat transfer by forced convection for flow of air inside a horizontal pipe.

D_p - 40mm

D_o - 20mm

specimen dimension - 23x300 mm

Set voltage

10V

60V

20V

Q(w) 10

T1(°C) 10

T2(°C) 10

T3(°C) 10

T4(°C) 10

T5(°C) 10

T6(°C) 27

T7(°C) 28

Temperature Gradient

Tm = Ts + Ta/2 K

Ts = T2+T3+T4+T5+T6/5 K

Ta = 303 K

Properties of air at Tm

Please enter a value rounded upto two decimal points

Mass Density of air

ρ_a = ^P⁄_{R.T_R} kg/m³

P_{atm - 101325 N/m²}

T_{atm - 303K}

R - 287 J/kg

Upto four decimal places

ρ_a =

kg/m³

V_air at orifice,

V_o = ^{Cd.(2.g.ha) ^1/2}⁄_{(1-(d_o/ d_p )⁴)^1/2} m/s

cd - 0.6

V_o =

m/s

Pressure drop

h_a = ^ρm.hm⁄_ρa m

ρm(mercury) -13600 kg/m³

manometer reading hm -25mm

h_a =

m

V_air in the tube

V_a = ^V_od_o²⁄_ds² m/s

V_a=

m/s

Reynolds number

Re = ^V_a.d_s⁄_γ

γ - 1.696*10^-5

Re =

Nusselt Number

Nu = ^{0.023(Re)^0.8(Pr)ⁿ}⁄

n = 0.4 for heating of fluid

n = 0.3 for cooling of fluid

Pr=0.699

Nu =

Heat transfer coefficient

h = ^Nu.k⁄_Ds W/m²k

k = 0.02756

h =

W/m²K

Heat transfer rate

Qc = ^h.A.⁄_(Ts-Ta) W

A = π.Ds.L

Qc =

W

Heat transfer by forced convection

Objective