Question

A cylindrical body of 300 mm diameter and 1.6 m height is maintained at a constant temperature of 36.5°C. The surrounding temperature is 13.5°C. Find out the amount of heat to be generated by the body per hour if rho = 1.025 kg/m3 ; cp= 0.96 kJ/kg C; v = 15.06 x 10 -6 m2 /s; k= 0.0892 kJ/m-h- C and β = 1/298 K-1 . Assume Nu = 0.12 (Gr. Pr) 1/3.

Answer 1

Answer:

Given: D = 300 mm = 0.3 m ; L = 1.6 m; t = 36.5°C; tₐ = 13.5°C; ρ = 1.025 kg/m³ ; c = 0.96 kJ/Kg°C; ν = 15.06×10⁻⁶ m²/s; k = 0.0892 kJ/m-h°C ; = $1/298$ K⁻¹; Nu = 0.12 (Gr. Pr)$^1^/^3$

Step-by-step explanation:

Grashoff Number, Gr = $L^3g\beta (t-t_a)/\upsilon$

= $1.6^3 . 9.81 . (1/298) . (36.5-13.5)/(15.06x10^-^6)^2$

= 1.3674 x 10¹⁰

Prandtl Number, Pr = μc/k = 1.025x(15.06x10⁻⁶x3600)x0.96/0.0892

Nusselt Number, Nu = hL/k = 0.12 (Gr.Pr)$^1^/^3$

= 241.75

∴h = (k/L) x 241.75 = 13.478 KJ/h m² °C

Heat Lost from the surface by natural convection.

Q = hA (t - tₐ)

= 467.5 KJ/h

This is the amount of heat to be generated

Answer 2

Answer:

Not known

Step-by-step explanation: