Q4-Q6: A device is used to cool hot copper spheres of diameter 5 mm from an average temperature of 200Cto 50C by letting them fall in air at 25°C and latm. Use drag coefficient C, = 0.4 and Whitaker correlation inyour calculations. Assume the spheres fall at their terminal velocities during the process.Q4improve the accuracy? Iteration is not required.) Determine the terminal velocity of a sphere. Is the use of C, = 0.4 appropriate? If not, how to

Re =ρVDμ =VDν chracterstics of air at Ts+T∞2=300+3502= 325 K using data book ν =5.12×10-5m2/s k =…

cool not coPP I in air at 25°C and latm. Use drag coefficient C the spheres fall at their terminal velocities durir terminal velocity of a sphere. Is the use of Cp = eration is not required. spheres of dlameter

cool not coPP I in air at 25°C and latm. Use drag coefficient C the spheres fall at their terminal velocities durir terminal velocity of a sphere. Is the use of Cp = eration is not required. spheres of dlameter

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.

Chapter6: Forced Convection Over Exterior Surfaces

Section: Chapter Questions

Problem 6.20P

See similar textbooks

Similar questions

When a sphere falls freely through a homogeneous fluid, it reaches a terminal velocity at which the weight of the sphere is balanced by the buoyant force and the frictional resistance of the fluid. Make a dimensional analysis of this problem and indicate how experimental data for this problem could be correlated. Neglect compressibility effects and the influence of surface roughness.
Air at 20C flows at 1 m/s between two parallel flat plates spaced 5 cm apart. Estimate the distance from the entrance to the point at which the hydrodynamic boundary layers meet.
5.6 A fluid flows at 5 over a wide, flat plate 15 cm long. For each from the following list, calculate the Reynolds number at the downstream end of the plate. Indicate whether the flow at that point is laminar, transition, or turbulent. Assume all fluids are at 40°C. (a) air, (b) , (c) water, (d) engine oil.
(COLLAB) Simulate projectile motion with air resistance in PhysLab. A shuttlecock is launched from the ground with an initial speed of 36.9688 m/s at an angle of 6.8583 degrees with respect to the horizontal. The shuttlecock experiences air resistance with a drag coefficient of 0.1931 in an environment where the air density is 0.9453 kg/m3. If the shuttlecock has a radius of 3.4 cm and a mass of 5.2 grams, what is the maximum height reached by the shuttlecock? Assume that the experiment is done near the surface of the earth (initHeight = 0) .
(b) In two dimensional boundary layer, shear stress was changed linearly from the solid surface toward y-axis until it reach the value of zero at y = ở. Based on Table 2 and setting given to you; (i) Derive the equation of displacement thickness and momentum thickness using Von Karman Approximation Method ; and (ii) Determine the accuracy of this method in determining the value of displacement thickness and momentum thickness. C5 Table 2: Equation of Velocity Profile Setting Equation wU = 2y/8 - (y/S² 1
* ZAIN IQ liı. SuspendEA IN A ROom, Ana TS Subjected To Air Flow Parallel To I... A 2m by 3m flat plate is suspended in a room, and is subjected to air flow parallel to its surfaces along its 3m long side as shown in the figure. The free stream air temperature, T, is 20°C and the velocity is 7 m/s. The total drag force acting on the plate is measured to be 0.86 N. Determine the average convection heat transfer coefficient for the plate. Air 20°C, 7 m/s L= 3 m. This problem has been solved! See the answer
The following equation may be used to estimate the take-off ground run for an aircraft: Equation has been attached as an image. Calculate the take-off ground run, from a runway at ISA-SL conditions, for a twin engine aircraft for which the following data may be assumed Aircraft lift-off speed 155 knots Max take-off gross weight 220 tonnes Wing planform area (S) 358 m Wing CL (t/o flaps deployed, a = 0) 1.1 Wing span 53.18 m Oswald efficiency factor, e 0.7 KGE = CD(IGE) / Co(OGE) 0.4 Co sum (fuselage, wing, tailplane and nacelle) 0.015 Co for undercarriage 0.021 Co for flaps at taking-off setting 0.0073 Coefficient of rolling friction, u 0.02 Engine thrust (assumed constant) 310 kN per engine It may be assumed that 1knot = 0.51444 m/s It may be assumed that 1knot = 0.51444 m/s
A student needs to measure the drag on a prototype of characteristicdimension d p moving at velocity U p in air at standardatmospheric conditions. He constructs a model ofcharacteristic dimension d m , such that the ratio d p / d m issome factor f . He then measures the drag on the model atdynamically similar conditions (also with air at standardatmospheric conditions). The student claims that the dragforce on the prototype will be identical to that measured onthe model. Is this claim correct? Explain.
Question 3 The aerodynamic derivative X, may be determined from the following expression: X -pU SCD %3D where p is the air density, S is the wing area, U is the airspeed, and Cp is the drag coefficient. Consider an aircraft of weight 68 kN and wing area 43 m?, flying straight and level under international standard atmosphere (ISA) conditions, where p 1.018 kg/m, at an airspeed of 155 m/s. The aircraft %3D has a drag polar Cp = 0.011 + where Ci is the lift coefficient. Calculate the value of X, at this flight condition. Give your answer in units of Ns/m.
During the glass plate production process, blocks with a temperature of 1400°C are produced. These blocks are 5cm thick and measure 1.5m wide and 1m high. If the thermal conductivity of the glass is 1.05 W/m2 and the surrounding air temperature is 550°C and the center of the block remains at 1400 degrees. a. What is the equation of flow dT/dx? b. Which is the function T(x)? Consider that the internal and external temperatures remain constant and calculate the flux from the center of the block to one of its sides. (L=2.5m)
This exercise is part of a series of problems aimed at modeling a situation by progressively refining our model to take into account more and more parameters. This progressive approach is very close to whatwhat do professional scientists do! contextWe want to lower a suspended load in a controlled way, so that it hits the ground with a speed whose modulus is not too great. To slow down the descent, we added a resort behind the mass (A), Lasuspended load (B) is connected by a rope passing through a pulley to another mass (A), which slides on a horizontal surface with friction.InformationThe masses of loads A and B are known.The mass of the rope itself is negligible (very small compared to the loads).The pulley has negligible mass and can rotate without friction.Load B is initially stationary and is at a known height h.The surface on which mass A is placed is horizontal.There is friction under mass A: the kinetic friction coefficient u, is known.The rope attached to mass A is perfectly…
An engineer is to design a human powered submarine for a design competition. The overall length of the prototype submarine is 2.24 m and its engineer designers hope that it can travel fully submerged through water at 0.560 m/s. The water is freshwater (a lake) at 7-15°C (p=999.1 kg/m3 and u= 1.138 ×103 kg/m-st. The design team builds a one-eighth scale model to test in their university's wind tunnel. The air in the wind tunnel is at 25°C (p= 1.180 kg/m3 and u = 1.849 ×10-5 kg/m-s) and at one standard atmosphere pressure. At what air speed do they need to run the wind tunnel in order to achieve similarity?