Heating and cooling with miniature impinging jets has been proposed for numerous applications. For a single round jet, determine the minimum jet diameter for which Equation 7.71 may be applied for air at atmospheric pressure (a) at
Want to see the full answer?
Check out a sample textbook solutionChapter 7 Solutions
Fundamentals of Heat and Mass Transfer
Additional Engineering Textbook Solutions
Automotive Technology: Principles, Diagnosis, And Service (6th Edition) (halderman Automotive Series)
Applied Statics and Strength of Materials (6th Edition)
Manufacturing Engineering & Technology
Thinking Like an Engineer: An Active Learning Approach (3rd Edition)
Heating Ventilating and Air Conditioning: Analysis and Design
Fox and McDonald's Introduction to Fluid Mechanics
- 11B.6. Transpiration cooling in a planar system. Two large flat porous horizontal plates are sepa- rated by a relatively small distance L. The upper plate at y = L is at temperature T₁, and the lower one at y = 0 is to be maintained at a lower temperature To. To reduce the amount of heat that must be removed from the lower plate, an ideal gas at To is blown upward through both plates at a steady rate. Develop an expression for the temperature distribution and the amount of heat qo that must be removed from the cold plate per unit area as a function of the fluid properties and gas flow rate. Use the abbreviation = pCpv,L/k. Answer: edy/Let 1-e k(T₁ - To) Φ L T-TL To - TL Problems 365 ; 9⁰ =arrow_forwardA long, cylindrical, electrical heating element of diameter D = 14 mm, thermal conductivity k = 251 W/m ⋅ K, density ρ = 2,805 kg/m3, and specific heat cp = 903 J/kg ⋅ K is installed in a duct for which air moves in cross-flow over the heater at a temperature and velocity of 30°C and 9 m/s, respectively. (a) Neglecting radiation, estimate the steady‐state surface temperature when, per unit length of the heater, electrical energy is being dissipated at a rate of 1,033 W/m.arrow_forwardHand Sanitizer (70% propanol gel) needs to be transported on a floor in a hospital from a central location per floor. The room farthest from the source is 17.5-m away. The hand sanitizer enters the tubing at 20°C and 275 kPa absolute and exits the tubing at atmospheric conditions. The tubing can Flowrate/velocity Calculation. Hand sanitizer be considered smooth; however, there are two (2) 90° curved elbows and four (4) Tee Run throughs, and one (1) foot value (Refer to the Loss for Fittings table in Canvas). The density of the hand sanitizer is 955 kg/m3 and the viscosity is 4.5 cP. What is the flow rate that can be obtained if the tubing diameter is 4.5-mm?arrow_forward
- A heat treat steel plate measures 3 m *1 m and is initially at 30 degree Celsius. It is cooled by blowing air parallel to 1 m edge at 9 km/hr. If the air is at 10 degree Celsius. Estimate the convective heat transfer from both sides of the plate.arrow_forwardShow all working explaining detailly each step. Answer Qb(i), (ii) & (iii)arrow_forwardA long, cylindrical, electrical heating element of diameter D = 12 mm, thermal conductivity k = 240 W/m ⋅ K, density ρ = 2,856 kg/m3, and specific heat cp = 908 J/kg ⋅ K is installed in a duct for which air moves in cross flow over the heater at a temperature and velocity of 30°C and 10 m/s, respectively. (a) Neglecting radiation, estimate the steady‐state surface temperature when, per unit length of the heater, electrical energy is being dissipated at a rate of 1,238 W/m.arrow_forward
- Show your complete solution.arrow_forwardSolve it correctly please. I will rate accordingly with 3votes.arrow_forwardO. Air with free stream temperature of 10 C is flowing over a flat plate (1.5m long and Im wide). The air is flowing along 1.5m side of the plate. The plate is maintained at 90'C. Find the velocity of air required to have a rate of heat dissipation as 3.75 kW. Use the correlations: Nu =0.664Reos Pro33 for laminar flow Nu, = (0.037RE-871)Pr3 for turbulent flow Take the properties p = 1.0877 kg/m u=2.029×10 m/s, k=0.028 W/mK, C,-1.007KJ/kg.K and Pr-0.703arrow_forward
- Consider two cases involving parallel flow of dry air at V = 4.5 m/s, T, = 45°C, and atmospheric pressure over an isothermal plate at T = 20°C. In the first case, Re= 5x 105, while in the second case the flow is tripped to a turbulent state atx = 0 m. At whatx -location, in m, are the thermal boundary layer thicknesses of the two cases equal? What are the local heat fluxes, in W/m?, at this location for the two cases? x = i m Jam i W/m? i W/m? I turbarrow_forwardYou are designing a pin-style heatsink for forced cooling of an IC. A small fan blows RT air into the heatsink at about 2.3 ? ? . The aluminum pins are 2mm in diameter and have a constant surface temperature of 120°?. The heatsink is 100mm x 100mm and the pins have an inline arrangement with a transverse pitch of 4mm and a longitudinal pitch of 6mm. What is the total heat dissipation of this heatsink? The pins are 30mm high. Note RT=25 celsiusarrow_forwardYou, a process design engineer, are tasked to build a powerplant that utilizes 1.5 metric tons of municipal solid wastes (MSW) per hour. In an industrial boiler, MSW is burned to heat and pressurize 1 kg/s of preheated water to high-pressure steam (44 atm, 450 °C). The high-pressure steam, moving at a linear velocity of 70 m/s, is then used to drive a high-pressure turbine. In a heat exchanger, the used steam from the outlet of high-P turbine at an intermediate pressure (10 atm, 250 °C) is used to preheat the water that will be fed to the boiler. This water is pumped from an underground reservoir at a low velocity (1 atm, 25 °C). After preheating the water, the intermediate-pressure steam leaving the heat exchanger is then used to drive a low-pressure turbine. Lastly, the steam from outlet of the low-P turbine leaves at a velocity of 10 m/s (at 1 atm and 100 °C) via an exhaust 10 m above the pump inlet. The industrial boiler is insulated, but due to the high temperatures and the nature…arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning