Consider a liquid metal
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Fundamentals of Heat and Mass Transfer
- Air at standard pressure flows across a flat plate at 3m/s. The temperature surface is 50oC and the surrounding temperature is 20o Consider a point 1m away from the leading edge of the plate. See Table A-15 in Appendix 1 for properties of air. Determine the Reynold’s number and Prandtl number for this flow at the location described above. Determine the local flow boundary layer thickness. Determine the local thermal boundary layer thickness for this flow. Find the local Nusselt number. Based on this Nusselt number, what is the local convective heat flux from the plate to the air?arrow_forwardAir at 200C flowing at 25 m/s passes over a flat plate, the surface of which is maintained at 270°C. Calculate the rate at which heat is transferred from both the sides of the plate per unit width over a distance of 0.25 m from the leading edge. Properties of air at 145°C are Prandtl number = 0.687; Viscosity = 2.8 X 10-5 m2/s and thermal conductivity = 3.49 X 10-5 kW/m.Karrow_forwardEngine oil at 100°C flows on the top surface of a 1-m-long flat plate maintained at 20°C. The oil’s freestream speed (u infinity) is 0.1 m/s. Find the engine oil properties from the table A.5 A. Evaluate the Reynolds number, local convection coefficient, heat flux and shear stress at the end of the plate (x = L). Is the air flow laminar or turbulent over the plate?B. Evaluate the average convection coefficient, average heat flux, average shear stress and drag force over the plate.arrow_forward
- Fluid flows over a flat plate, 1.2 m long. The direction of flow is along the length of the plate and parallel to the surface of the plate. The plate is held at a constant temperature of 283 K. Velocity and temperature profiles are assumed to be linear inside the boundary layers. The free stream temperature of the fluid is 340 K and it travels at 5 m/s. The fluid properties are as follows: thermal conductivity = 0.029 W/mK, density = 0.92 kg/m3, viscosity = 12.9 x 10-6 Pa.s, and specific heat capacity = 1003 J/kgK. The value of the Nusselt number at the tailing edge of the flat plate is: [ans1] The convective heat transfer from the middle of the flat plate is: [ans2] W/m2 step by step working out piease, hit final answer is 145, -281 respectivelyarrow_forwardCold fluid flows at a velocity of 8 m/s over a hot flat plate. The flow is laminar, and the velocity and temperature profiles are assumed to be linear. The fluid properties are as follows: density ρ=1.14kg/m3, viscosity μ=18.2×10−6Pa s, specific heat capacity cp=1,008J/kgK, and thermal conductivity k=0.023W/mK. What is the thickness of the thermal boundary layer at the position x=2mm downstream of the leading edge? Give your numerical answer in mm to 1 decimal place.arrow_forwardWater at 60° C flows over 2.5 cm square flat plate 90°C at a velocity of 4 m/s. 1- Calculate the drag force , Xcritical 2- If the flat plate is exposed to the natural air convection at 60 °C instead of water with same values of temperatures and length calculate Rayleigh number.arrow_forward
- An expression for the laminar velocity profile on a flat plate is u=C1sin(C2y)+C3 Where the argument of the sine function is in radians. Using the three common physicalconditions that the velocity profile should satisfy, determine a) the constants C1, C2, and C3.b) the nondimensional velocity profilec) the boundary thickness (δ/x) as a function of lengthd) the skin friction coefficient, Cf as a function of lengthe) displacement thickness (δ*/x) as a function of lengthf) the momentum thickness (θ/x) as a function of lengthg) the drag force (FD) on both sides of the platearrow_forwardA thermocouple junction is in the form of 8 mm diameter sphere. Properties of materialare: Cp = 420 J/kg-K; ρ = 8000 kg/m3 ; k = 40 W/m-K; h = 40 W/m2 -K. This junction isinitially at 40 oC and inserted in a stream of hot air at 300 oC. Find the following:a. Time constant of the thermocouple.b. The thermocouple is taken out from the hot air after 10 seconds and kept in still airat 30 oC. Assuming the heat transfer coefficient in air is 10 W/m2-oC, find thetemperature attained by the junction 20 seconds after removal from hot air.arrow_forwardConsider the laminar boundary layer flow of an isothermal fluid ( U ∞ , T ∞ ) over a flat isothermal wall ( T 0 ). At a certain distance x from the leading edge, the local skin friction coefficient is C f , x = 0.0066. What is the value of the local Nusselt number at the same location if the Prandtl number is Pr = 7?arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning