(B) Air at 27°C flows over a flat plate with a velocity of 3 m/s. Calculate the boundary layer thickness (8) at a distance 25 cm from the leading edge of the plate. The physical properties of air are: p=1.17 kg/m' and -1.85×10 m³/s. 8 4.64 B x Re 1/2

(B) Air at 27°C flows over a flat plate with a velocity of 3 m/s. Calculate the boundary layer thickness (8) at a distance 25 cm from the leading edge of the plate. The physical properties of air are: p=1.17 kg/m' and -1.85×10 m³/s. 8 4.64 B x Re 1/2

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

Engine oil at 40°C flows over a 20-m-long & 3-m-wide smooth flat plate with a free-stream velocity of 50 m/s. Determine the drag force acting on upper side of the plate when:a) Flow is parallel to plate length.b) Flow is parallel to plate width.
Atmospheric air with free flow velocity U_∞= 30 m/s flows through a circular cylinder at T_∞= 250 K and D = 2.5 cm diameter. The surface of the circular cylinder is kept at a uniform temperature T_w = 350 K.The CD drag coefficient is 1.1. (D=1 cm- 3 cm and U_∞= 10 m/sec 30 m/s)(a) Calculate the average heat transfer coefficient ( h ̅_m,W/m2K)(b) Determine the amount of heat transfer (Q, W) per 1 m length of the cylinder(c) Calculate the drag force (FD, N) acting on the 1 m length of the cylinder FD=0.1 A=0.34 D=2.9 cd=1.2
A 1.5-m-long and 0.5 m wide flat plate is immersed in water flow with velocity of kg 5 m/s. (F = 1000 =1.02 x10- m Determine; (a) The boundary layer thickness at leading edge of the plate, (b) The drag coefficient and the drag force, (c) the drag coefficient and force, if the flow is laminar at the entrance (Rex, ait= 106), (d) the drag force, if the roughness height & is 0.2 mm on the plate.
Engine 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.
A high speed train has a design speed of 120 km/hr. A flat plate of length 200 m with a width of 9 m is used for the simulation of train. Determine the approximate power required to overcome surface frictional resistance . ( Air density :1,2 kg m3 viscosity: 1,5 x 10-5 m2/ s )ANSWER: 69,6 k W
Wind flows over a flat plate of length L = 25 mm and width W = 8 mm. The plate is maintained at a constant temperature of 32 °C on both sides. using an electric heater generating heat at a rate of Q = 0.5 W which is dissipated to air from both sides of the plate. Consider the temperature of the wind/air as 20 °C and assume that the wind speed does not exceed 100 m/s. The properties of air at this temperature are given as; specific heat capacity Cp = 1.005 kJ/kg-K, thermal conductivity k = 0.0253 W/m-K, Density p = 1.19 kg/m³, and kinematic viscosity v = 1.522 x 10 5 m²/s.
Air at 10°C and 1 atm is flowing parallel at a velocity of 15.5 m/s over the top flat surface of copper plate. The top surface of the copper plate is 0.03m by 0.03m square. The temperature of copper plate is uniform at 65.6°C. For laminar flow, calculate the dimensionless Reymolds number (Nre) and Nussel number (NNu). Table A.3-3a. Physical Properties of Air at 101.325 kPa (1 Atm Abs), SI Units Bx (Bp²/1?) T (kJ/kg · u x T (Pa ·s, k (W/m 103 (1/K • (°C) T (K) (kg/m³) K) -17.8255.41.379 1.0048 1.62 × 6s or kg/m · s) · K) Npr (1/K) m³) 0.022500.7203.92 2.79 x 108 O 273.21.293 1.0048 1.72 × (0-5 0.024230.7153.65 2.04 × 108 10.0 283.21.246 1.0048 1.78 ×/0 0.024920.7133.53 1.72 x 108 37.8 311.01.137 1.0048 1.90%/0-S 0.027000.7053.22 1.12 x 108 Select one: O A. NRe = 27826.58; NNu =98.58 O B. NRe = 23215.74; NNu =152.68 O C. NRe = 27826.58; NNu = 152.68 O D. NRe = 23215.74; NNu =98.58
Air with uniform velocity of U is flowing over flat square-shape plates with different arrangements given in figure below. One plate is used in arrangement (a), whereas four square plates are used in the arrangement (b). All the plates are the same size. What is the frictional forces ratio (Fo/Fa)? (Note: Assume laminar boundary layer condition along the plate arrangements) U (a) (b) Yanıt:
Air at 15°C flows at 10 m/s over a flat plate of length 3 m. Using one-seventh power law of the turbulent flow, what is the ratio of local skin friction coefficient for the turbulent and laminar flow cases? (The kinematic viscosity of air is 1.470 × 10−5 m2/s.) (a) 4.25 (b) 5.72 (c) 6.31 (d ) 7.29 (e) 8.54
Air at 305 K flows at 4 m/s over a flat plate at 350 K. The air properties are as follows: density =1.1 kg/m3, viscosity =18.1×10−6 Pa.s, specific heat capacity =1005 J/kgK, and thermal conductivity =0.024 W/mK. The velocity and temperature profiles are assumed to be linear, giving the local Nusselt number to be Nux = 0.289 Rex1/ 2Pr1/3. The flow will become turbulent at a Reynolds number of 5×105. Assume the width of the plate perpendicular to the air flow is 1 m. At what distance from the leading edge does the flow become turbulent? ________m What is the heat transfer at the point of transition? ___________W What is the total heat transfer along the length of the plate where the flow is laminar? __________W
Calculate the heat transfer from a 60 cm x 60 cm plate on which air flows at 40⁰C and. The plate temperature is 100⁰ C while the air speed is 5 m/s.Find the thickness of the boundary layer at a distance of x = 20 cm, for the same data in problem "number 1 In the picture below"
8- Air (p = 1.21 kg/m') flows over a thin flat plate 1 m long and 0.3 m wide. The flow is uniform at the leading edge of the plate. Assume the velocity profile in the boundary layer is linear, and the free stream velocity is 2.7 m/s. Using control volume (abcd) shown in figure, compute the mass flow rate across surface (ab). Determine the magnitude and direction of the x- component of the force required to hold plate stationary. [3.9×10 kg/s ; -3.5x10 N]