3. A blacktop road surface 18.3 m. wide receives solar radiation at the rate of 284 W/m² at noon and 189 W/m² is lost by forced convection (the remaining is lost by radiation, and you do not need to account for it). A steady wind at 300 K blows across the road. A. Determine the wind velocity that will cause the road surface to be at 308K. Assume that the flow is laminar. B. Once you calculate the wind velocity, comment if this was a reasonable assumption. C. If your answer to part B is "no" - recalculate the velocity assuming turbulent flow CE TO

3. A blacktop road surface 18.3 m. wide receives solar radiation at the rate of 284 W/m² at noon and 189 W/m² is lost by forced convection (the remaining is lost by radiation, and you do not need to account for it). A steady wind at 300 K blows across the road. A. Determine the wind velocity that will cause the road surface to be at 308K. Assume that the flow is laminar. B. Once you calculate the wind velocity, comment if this was a reasonable assumption. C. If your answer to part B is "no" - recalculate the velocity assuming turbulent flow CE TO

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.68P

See similar textbooks

Similar questions

A radiant-heating system is installed in the plaster ceiling of a room 36 ft long by 18 ft wide by 9 ft high. Assume direct radiation. The temperature of the concrete floor is maintained at 75°F. The temperature of the air passing through the room is held at 75°F. If the required heat supply to the floor is 8000 BTU/hr, calculate the necessary temperature at the ceiling surface. How much heat is transferred to the air, in BUT/hr? Emissivity of plaster = 0.93; absorptivity of concrete = 0.63. The convective heat-transfer coefficient between the ceiling and the air is given by the equation hc = 0.20 (AT)¹/4.
31. A uniformly heated square plate of 2 ft × 2 ft is exposed to cold air at 80 F. The heater output remains at a constant value of 1 kW. Air, at atmospheric pres- sure, flows over the plate at a velocity of 16.5 ft/s. Find the average temperature of this plate. [Ans.: - 513 F].
A circular pipe with inner diameter of 0.02 m has its inner surface covered with water at 303K. Dry air is flowing inside the pipe at the velocity of 10 m/s. The temperature of air is 303K and its pressure is at 1 atm. Calculate:a) Mass transfer from the 0.01 m length pipeb) Rate of heat transfer from pipe to air by mass convection and heat convection.
Atmospheric air with a temperature of 300 K flows on both sides of a thin, rectangular, flat plate that is maintained at 600 K. The plate is 150 mm long and 75 mm wide. The free stream velocity is 2.5 m/s; plate's length is in the direction of air flow. Draw a labeled sketch and determine: a) The drag force acting on the plate. b) The rate of heat loss from the plate.
need some help with this one. The water vapor pressure of ambient air is 19 mmHg, and the wind speed is 1.7 m/s. Calculate the maximum evaporative heat loss (Emax in watts). (Assume skin temperature is 35°C; vapor pressure at 35°C is 42 mmHg., and a standard worker) -53 O 232 O 232 O 30 O -30 O 53
Calculate the rate of heat transfer by radiation from an unlagged steam pipe, 50 mm, o.d. at 393 K (120° C) to air at 293 K (20° C). Assume emissivity 'e' of 0.9.
The air at 1 ATM and 35⁰c flow through a cylinder 5 cm in diameter, at Velocity 50 cm/s. The surface temperature of the cylinder is guarded at 150⁰c. *)Count the heat Each cylinder length.
24. Water at 80 F is flowing over a flat plate with a velocity of 8 ft/s. The plate is5 ft long. Find and plot the heat transfer coefficient as a function of the platelength.
Provide the answers with clear explantion and images. Coolant flowing through a radiator at the rate of 3 kg/s are cooled from 105 0C to 81 0 The specific heat capacity of coolant and air are 4.19 kJ/kg K and 1.13 kJ/kJ/K respectively. Th overall heat transfer coefficient from gas to water is 140 W/m2 K. Calculate the surface area required for the radiation if the vehicle speed is 100 km/h. Consider the density of air as 1.225 kg/m3.
A horizontal-axis wind turbine with rotor 80m in diameter is 35% efficient in 18m/s wind at 0.977 atmospheric pressure and 25°C. a. Calculate the total amount of power the wind turbine would produce in those winds. b. Estimate the amount of power the turbine would produce if the altitude increased by 1500m and the temperature increased to 30°C. TABLE 6.1 Density of Dry Air at a Pressure of 1 Atmosphere Temperature Temperature Density Density Ratio (°C) (°F) (kg/m³) (KT) -15 ៦ ៩៩ ៨ ៩ t = w c! ម៉ត់ -10 5 15 5.0 14.0 23.0 32.0 41.0 50.0 59.0 68.0 77.0 86.0 95.0 104.0 1.368 1.342 1.317 1.293 1.269 1.247 1,225 1.204 1.184 1.165 1.146 1.127 1.12 1.10 1.07 1.05 1.04 1.02 1.30 0.98 0.97 0.95 0.94 0.92 "The density ratio Kr is the ratio of density at 7 to the density at the standard (boldfaced) 15°C. TABLE 6.2 Air Pressure at 15°C as a Function of Altitude Altitude (meters) 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 Altitude (feet) 0 656 1312 1968 2625 3281 3937 4593 5249 5905 6562…
The velocity of fluid close to the boundary layer for free or natural convection can be assumed as ........................ Please fill the blank with one of these two choices (Zero or non-zero)
In cold climates, weather reports usually give both the actual air temperature and the "wind-chill" temperature, which can be interpreted as follows. At the prevailing wind speed there is a rate of heat loss per unit area q, from a clothed person for an air temperature Te. The wind-chill temperature Twe is the air temperature that will give the same rate of heat loss on a calm day. Estimate the wind-chill temperature on a day when the air temperature is -10°C and the wind speed is 10m/s, giving a convective heat transfer coefficient of 50 W/m² K. A radiation heat transfer coefficient of 5 W/m² K can be used, and under calm conditions the convective heat transfer coefficient can be taken to be 5.0 W/m² K. Assume a 3 mm layer of skin (k = 0.35 W/m K), clothing equivalent to 8 mm-thick wool (k = 0.05 W/m K), and a temperature of 35°C below the skin. Also calculate the skin outer temperature.