A long rectangular plate of AISI 304 stainless steel is initially at 1200 K and is cooled by an array of slot jets (see Figure 7.17). The nozzle width and pitch are
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Fundamentals of Heat and Mass Transfer
- A plane-inclined pad thrust bearing is 160mm wide and 40mm long in the direction of sliding. The sliding velocity is 6 m/s and the bearing is supported so that the inlet film thickness is always three times the outlet film thickness. A load 18 kN is carried by the bearing and Tellus 37 oil is supplied at an inlet temperature of 40̊ C. Assuming that 80% of the heat generated in the bearing is carried away by the oil, describe the operating characteristics of the bearing (Pm, Q, F, tm,). Density is 875 kg/m3 and specific heat is Cp=1.880 J/g-K.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_forwardYou are designing an IC heatsink which uses round pins in cross-flow. The heatsink must dissipate 3000W. The heatsink has 10 rows of 8 columns of round pins with a diameter of 1mm. The pins have longitudinal and transverse pitch of 6mm. The incoming air is at 25oC with a velocity of 3 m/s. Assume fluid properties are constant. If the pins are arranged in-line: a) Find the Reynold’s Number b) Find the Nusselt Number c) If the pins are 30mm tall, how hot must the pin surface be (average) to dissipate the proper amount of heat?arrow_forward
- 8. A lead pipe has 2 cm inside diameter, 3 cm outer diameter, length of 130 cm. Liquid water at 4°C flows through the pipe with a bulk velocity of 0.03 km/hr. Air is blown around the outside of the pipe at 20 deg C. The inside wall of the said pipe has a temperature of 8 deg Celsius. Density of liquid water= 1000 kg/m³ Cp water=4.210 J/kgK Viscosity of liquid water= 1.5674 x10° Pa.s thermal conductivity of lead = 35 W/mK thermal conductivity of water = 0.575 W/mK Find: Overall heat coefficient (U) based on outside surface area b. System's heat transfer rate Prandtl (Pr), Reynolds (Re) numbers and type of flow а. с.arrow_forwardPlease show all steps, not Ai generated, has been wrong before. I need to understand the process.arrow_forwardAtmospheric air at 5°C enters a thin walled 12cm diameter 20m long isothermal pipe (Ts=constant) at a velocity of 2.5m/s and leaves at 19°C. Estimate the surface temperature Ts.arrow_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_forward. Oil enters a 1.25-cm diameter,3-m long tube at 38°C. The tube wall is maintained at 66°C, and flow velocity is 0.3 m/s. What is the total heat transfer to the oil and oil exit temperature? Assume an exit temperature of 50°C. Temperature (°C) p(kg/m³) u (kg/m sec) Cp J/hg °C) k(W/m °C) 0.210 0.0725 0.0320 40 0.144 867.05 864.04 1964 60 2047 0.140 80 852.02 2131 0.138arrow_forwardcan you please work it all please pleasearrow_forward
- Solve for the latent heat of water at Tw = 28C(and. λw = 2435 kJ/kg)arrow_forwardAir flows inside a tube 60 mm in diameter (d) and 2.1 m long (l) at a velocity w = 5 m/sec. Find the heat-transfer coefficient α if the mean air temperature tf = 100oC. Note: Write your answer in space provided without the unit (the answer is in kcal/m2-hr-oC, one decimal places)arrow_forwardA vehicle carrying refrigeration box is moving with a speed of 24 m/s on a road withambient temperature of 323 K. The dimensions of box are 3 m(H) × 4 m (W) × 10 m (L).Assume a wall temperature of 283 K and air flow is parallel to the longest side of the box.Neglecting the heat loss from the front side and backside of the box, calculate heat lossfrom four surfaces. For flow over flat surfaces useNu = 0.036(Re)0.8(Pr)1/3The properties of air at bulk mean temperature are : = 1.165 kg/m3, Pr = 0.701, cp = 1005 J/kg – K, = 16 × 10–6m2/sarrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning