if l is increased and everything remains the same what will happen to h?
if l is increased and everything remains the same what will happen to h? 6.25 Experimental...
A) Determine the convection heat transfer coefficient for the flow of air. [W/m2·°C] B) Determine the convection heat transfer coefficient for water. [W/m2·°C] The velocity of the fluid is 9 m/s in an 8-cm diameter and 7-m-long tube when the tube is subjected to uniform heat flux from all surfaces. Use fluid properties at 25°C. Water or Air D 8 cm L=7 m Given: The properties of air at 25°C are: k 0.02551 W/m."C v 1.562 10-5 m2/s Pr =...
please explain (10%) Heat transfer in clean, round pipes follows the empirical correlation, Nu 0.0225 Re8 Pr04 hD Dvp Pr In a pilot-scale unit, a heat-transfer coefficient of 300 W/m2.K is measured for fluid flowing at 5 m/s through a 3 cm diameter pipe. Calculate the heat-transfer coefficient in W/m2 K when the process is scaled up to a geometrically similar 15 cm diameter pipe, using the same fluid. a) 60 b) 10 c) 300 d) 500
(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...
A long horizontal cylinder with diameter of d-60 mm and length of L-1 m is at 27°C and is placed in a quiescent environment at 4°C. Find the cooling rate (q). End effects (heat transfer from the two ends of the cylinder) are negligible. The following relation (Churchill and Chu) for Nusselt number can be used. Air (T-288.5K): v=14.87x10° m2/s, k=0.0254 w/m-K, α=21.0x10-6 m2/s, Pr-0.71, B-3.47x1031/K. 1. Quiescent air 7,-4°C 0.06 m diameter T 27 C L=1m MUD 10.60 +...
Water at an average velocity of 3.5 m/s flows through a 5-m-long stainless steel tube (k = 14.2 W/m °C) in a boiler. The inner and outer diameters of the tube are Di = 1.0 cm and Do = 1.4 cm, respectively. If the convection heat transfer coefficient at the outer surface of the tube where boiling is taking place is ho = 8400 W/m2 • °C, determine product of the overall heat transfer coefficient Ui by the inner surface...
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...
on of a horizontal water pipe shown in the figure is passing through a large room. The walls of interpolate properties. 1 in the room are at the same temperature as the air. You do not need to 0.0254 m, σ-5.67x 108 W/(m2 K4) Pipe т,-65°C Air T-22 C D= 6cm L 393.6 inches (4 pts) Calculate the Rayleigh Number (Ra) for this configuration. Check your answers, no partial credit on this problem. a. (4 pts) If the free convection...
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...
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...
6 Water is heated in a pipe by exchanging heat with a warmer fluid that flows outside the pipe. Inside diameter of the pipe is dn 0.045 m and outside diameter dour0.05 m. Mean velocity of the water in the pipe is um-0.31 m/s and the bulk temperature is 323 K (density 988 kg m-3; viscosity 0.00055 kg m' sı. Pr 3.56, thermal conductivity k 0.64 W m1 Kt). The material of the pipe has thermal conductivity k 0.61 W...