The correct Nusselt number to calculate the average heat flux along the length of the flat plate is option
B. . Because to calculate the average values we use
Average Nusselt number = 2 (Local Nusselt Number)
= 2 ()
=
Problem 2) Consider convection heat transfer over a flat plate, as shown in the figure. The...
(a) (iWhen is heat transfer through a fluid by conduction or by convection? For what case is the rate of heat transfer higher? How does the convection heat transfer coefficient differ from the thermal conductivity of a fluid? (ii) Explain the physical significance of Nusselt number (ii) By definition, discuss hydraulic diameter. Obtain an expression for hydraulic diameter of a circular tube of diameter, D (b) The local atmospheric pressure in Gboko, Benue State Nigeria (elevation 1610 m), is 834...
Exercise 2 Air at 20 °C and 1 atm flows over a flat plate at 50 m/s. The plate is 300 cm long and is maintained at 60C. The width of the plate is 2 m. The critical Rec = 5 x 105 The properties are Conductivity k = 0.0263 W/mK, kinematic viscosity nu = v = 15.89 x 10-6 m²/s, Prandtl number is Pr=0.707 Density rho = p = 1.128 kg/m3 1. Determine the critical length Xc 2. Determine...
Air at T=25°C and pressure P=1 bar flows over a square plate with a velocity V=1 m/s. This plate has a length L= 1 m and it is heated over its entire length; the plate temperature is constant Tp=100°C. The following data are given. For air: dynamic viscosity: mu = 1.9*10–5 kg/(m.s); density: rho = 1.05 kg/m3; conductivity k = 0.03 W/(m K); Specific heat Cp = 1.007 kJ/(kg K); Prandtl number Pr = 0.7 For laminar flow over a...
Use the integral method for boundary layer flow and convective heat transfer over a flat plate heated by maintaining a constant heat flux q"w, for the case of very low Prandtl number, Pr0. Assume that the free stream velocity of the fluid, U, and free stream temperature, T-do not vary with x. Using the integral form of energy equation, show that under these conditions: (a) the temperature profile, (T- T) is given by, 41 2 CT-T oa (b) the wall...
Question 1 [40 Points] Liquid mercury at 300 K flows over a flat surface at a free stream velocity 0.15 m/s. The flat plate is smooth with a width of 0.25 m and length 0.5 m and is kept at a uniform temperature of 400 K. The flow is parallel to the longer dimension of the plate. Find out: 1. MINIMUM LOCAL convective heat flux, q min and its location (60%) 2. Total convective heat transfer rate, q (40%) Use...
Heat Transfer problem, ch9 Will give instant thumbs up! Problem 14: Also, after going over example problem 9-2, determine the heat transfer by natural convection for the hot plate facing down with 0 = 30°. Cooling of a Plate in Different Orientations Consider a 0.6-m x 0.6-m thin square plate in a room at 30°C. One side of the plac is maintained at a temperature of 90°C, while the other side is insulated, as shown in Fig. 9-18. Determine the...
External problem 1 - Chapter 8: Engine heat transfer correlation The following table reports experimental results obtained for an engine overall Nusselt number for different engine speeds. N (rpm) 1000 Nu/1000 186 5000 4000 3000 2000 752 653 548 319438 The engine tested is a single cylinder engine with a 0.12 m bore and 0.12 m stroke. Assume k0.06W Im.K and 20x10 Ns/m2. The volumetric efficiency is e, 0.85 b) Write In( Nu) in function of InN), Conclude the heat...
4) Air at 101 kPa and 360 K flows at 15 m/s over a flat plate maintained at 300 K Assume that the transition Reynolds number is 5x10 (0.332R 12Pr1/3 Re < 5 x 105 0.029Repr0:43 5 x 105 < Re <3 x 107 Assume that k-0.03 W/( mK), 20x10* m?ls, Pr-0.7.p=1.16 kg/m a) If the plate is 2 m long, sketch the local heat transfer coefficient over the plate. Specify the functional form of h with respect tox b)...
2. (10 points) A pharmaceutical fluid is sterilized by heating it from 25 to 75 °C as it moves at 0.2 m/s through a straight thin-walled stainless steel tube of 12.7-mm diameter that is 10 m long. A uniform heat flux is maintained by an electric resistance heater wrapped around the outer surface of the straight tube. The pharmaceutical fluid properties may be approximated as: p = 1000 kg/mº, cp = 4 kJ/kg-K, u = 2.102 kg/s-m, k = 1...
I need Q5 Heat transfer Problem(.) In an experiment, it is found that the local convection coefficient on a flat plate of length L is given by: (10 marks) h,-o923 (k/x){(V. ?.?)/p)as, where k, V, p, and ? are constants. Determine the average convection coefficient over the plate h Problem (5) (10 marks) Milk is flowing with a mass flow rate m 0.6 kg/s, in a pipe with internal diameter - 3 cm. Its initial temperature is 50 °C and...