An object of characteristic length Z = 0.5 m is 10°C warmer than the surrounding fluid, which is flowing at a velocity of 0.5 m/s. Determine the Reynolds number, the Grashof number, and the ratio Gr,/ Re for T, = 80°C, where Ty is the film temperature. Consider the fluid to be either air at atmospheric pressure or liquid water. GrLair 1.1066 Rezar 11468.73165 (Gry/Re) 0.54804 Gri.water 3.750 Rewater 684380.28 (Gry/Re) water 0.008

An object of characteristic length Z = 0.5 m is 10°C warmer than the surrounding fluid, which is flowing at a velocity of 0.5 m/s. Determine the Reynolds number, the Grashof number, and the ratio Gr,/ Re for T, = 80°C, where Ty is the film temperature. Consider the fluid to be either air at atmospheric pressure or liquid water. GrLair 1.1066 Rezar 11468.73165 (Gry/Re) 0.54804 Gri.water 3.750 Rewater 684380.28 (Gry/Re) water 0.008

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.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.20P

See similar textbooks

Similar questions

An electrical transmission line of 1.2-cm diameter carries a current of 200 amps and has a resistance of 310-4 ohm per meter of length. If the air around this line is at v, determine the surface temperature on a windy day, assuming a wind blows across the line at 33 km/h.
Calculating the Reynolds numbers at the end of the plate for the following fluid flowing over a 15cm long plate at a speed of 5 m / s at 40 ℃ and whose kinematic viscosities are given; Determine if the flow is laminar or turbulent flow or flow in the transition zone.For air ϑ_Air = 17.6x 〖10〗 ^ (- 6) m2 / sFor CO2 ϑ_CO2 = 9.07x 〖10〗 ^ (- 6) m2 / sFor water = 0.658 〖10〗 ^ (- 6) m2 / sFor engine oil ϑ_Oil = 240x 〖10〗 ^ (- 6) m2 / h
A 20 °C water flows to 50cmx60cm flat plate with velocity of 6m/s . The flat plate surface temperature is maintained at 40 °C . The air flows parallel to the 50cm side of the plate. If the kinematic viscosity of water is 78x10-8 m2/s, at what length the flow become turbulent? If the average laminar heat transfer coefficient of water is 7740W/m2 °C , what is the overall heat transfer at the laminar section?
Calculating the Reynolds numbers at the end of the plate for the following fluid flowing over a 15cm long plate at a speed of 5 m / s at 40 ℃ and whose kinematic viscosities are given; Determine if the flow is laminar or turbulent flow or flow in the transition zone. (a)kinematic viscosity for air 17,6*10-6 m2/s (b) kinematic viscosity for CO2 9,07*10-6 m2/s (c) kinematic viscosity for water 0,658*10-6 m2/s (d) kinematic viscosity for oil 240*10-6 m2/s
Hydrodynamic journal bearings have been widely used to support high speed rotating machinery such as turbines and compressors because of their superior durability and load carrying capacity. Therefore, the bearings are important machine elements for enhancing the quality of the rotating machinery.Assuming that oil flow in a journal bearing can be treated as parallel flow between two large isothermal plates as shown in Figure 1 with one plate moving at constant velocity of 20 m/s and the other stationary. Consider such a flow with a uniform spacing of 1.8 mm between the plates. The temperatures of upper and lower plates are 45°C and 12°C, respectively. By simplifying and solving the momentum and energy transport equations in Appendix B, Derive the velocity and temperature profile in the oil. State all your postulateand assumptions. This is an old question not graded
During a cold winter day, wind at 55 km/h is blowing parallel to a 4m high and 10m long wall of a house. If the air outside is at 5 degrees Celsius and the surface temperature of the wall is 12 degrees Celsius , determine the rate of heat loss from the wall by convection. What would your answer be if the wind velocity has doubled? From Table A-1:thermal conductivity, k = 0.0246 W/m degrees Celsiusviscosity, v = 1.4 x 10^-5 m^2/sPrandtl no. Pr = 0.717
Oil flow in a journal bearing can be treated as parallel flow between two large isothermal plates with one plate moving at a constant velocity of 8 m/s and the other stationary. Consider such a flow with a uniform spacing of 0.7 mm between the plates. The temperatures of the upper and lower plates are 40°C and 15°C, respectively. By simplifying and solving the continuity, momentum, and energy equations, determine (a) the velocity and temperature distributions in the oil, (b) the maximum temperature and where it occurs, and (c) the heat flux from the oil to each plate.
Water at 45.0oC flows over a large plate at a velocity of 30.0 cm/s. The plate is 1.0 m long (in the flow direction), and its surface is maintained at a uniform temperature of 5.0oC. Calculate the steady rate of heat transfer per unit width of the plate. Properties The properties of air at 1 atm and the film temperature of (Ts+T∞)/2 = (5+45)/2 = 25°C are: ρ = 996.6 kg/m3, k = 0.610 W/m.oC, μ = 0.854x10-3 kg/m.s, Pr = 5.85
Mercury at 25°C flows over a 3-m-long and 2-m-wide flat plate maintained at 75°C with a velocity of 0.01 m/s. Determine the rate of heat transfer from the entire plate.
Consider a bullet piercing through calm air during a short time interval in which the bullet’s speed is nearly constant. Determine if the time-averaged airflow over the bullet during its flight is one-, two-, or three-dimensional
The flow velocity of air over a flat plate of dimension 1160 ×610 ×25 mm at 30 OC is 3.2 m/s. The top surface of the plate is maintained at 110 OC. Calculate the bottom temperature of the plate at steady state.
A fluid with a constant density of 961 kg/m3 and a constant viscosity of 1.419×10-3 Kg/m.s is flowing over a flat plate at a stream free velocity of 0.87 m/s. If the plate has a length of 2 m, answer the following: 1.What is Reynolds number at a point that is (1/4)L down the entrance? 2.Is the flow laminar or turbulent? 3.Calculate the thickness of the boundary layer in mm at (1/4)L down the entrance 4.Calculate the drag coefficient at (1/4)L down the entrance