Q. For a particular engine, the underside of the crankcase can be idealized as a flat plate measuring 80 cm by 20 cm. The engine runs at 80 km/hr and the crankcase is cooled by the air flowing past it at the same speed. Find loss of the heat from the crank case surface (t S = 25 degree Celsius). Assume the boundary layer to be turbulent

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Q. A flat plate 1 m by 1 m is placed in a wind tunnel. The velocity and temperature of free stream air are 80 m/s and 10 degree Celsius. The flow over the whole length of the plate is made turbulent by turbulizing grid placed upstream of the plate. Find the thickness of hydrodynamic boundary layer at trailing edge of the plate

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Q. A flat plate 1 m by 1 m is placed in a wind tunnel. The velocity and temperature of free stream air are 80 m/s and 10 degree Celsius. The flow over the whole length of the plate is made turbulent by turbulizing grid placed upstream of the plate. Find the heat flow from the surface of the plate

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Q. The concept of hydrodynamic boundary layer was first suggested by

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Q. The free stream undisturbed flow has a uniform velocity U INFINITY in the

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Q. The thin layer where velocity changes continuously is called

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Q. The conditions for flow beyond the boundary layer and its outer edge are

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Q. The pattern of flow in the boundary layer is judged by the

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Q. The transition from laminar to turbulent pattern of flow occurs at values of Reynolds number between

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Q. The entrance length required for the flow to become fully-developed turbulent flow is dependent on

(i) Surface finish

(ii) Downstream conditions

(iii) Fluid properties

Identify the correct answer

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Q. What is the value of thickness of the boundary layer at leading edge of the plate?

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Q. The boundary layer thickness is taken to be at a distance from the plate surface to a point at which the velocity is given by

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Q. Glycerin at 10 degree Celsius flows past a flat plate at 20 m/s. Workout the velocity components at a point P(x, y) in the fluid flow where

x = 2 m from the leading edge of the plate
y = 5 cm from the plate surface

For glycerin at 10 degree Celsius, kinematic viscosity = 2.79 * 10¯³ m²/s

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Q. A plate 0.3 m long is placed at zero angle of incidence in a stream of 15 degree Celsius water moving at 1 m/s. Find out the stream wise velocity component at the mid-point of the boundary layer. For water at 15 degree Celsius

p = 998.9 kg /m³
µ = 415.85 * 10¯² kg/hr m

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Q. Air at 25 degree Celsius flows over a flat surface with a sharp leading edge at 1.5 m/s. Find the boundary layer thickness at 0.5 from the leading edge. For air at 25 degree Celsius, kinematic viscosity = 15.53* 10n¯⁶ m²/s

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Q. Local skin friction coefficient is given by

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Q. A plate 0.3 m long is placed at zero angle of incidence in a stream of 15 degree Celsius water moving at 1 m/s. Find out the maximum boundary layer thickness. For water at 15 degree Celsius. For water at 15 degree Celsius

p = 998.9 kg /m³
µ = 415.85 * 10¯² kg/hr m

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Q. Shear stress at the middle of the plate is given by

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Q. Boundary layer thickness is given by

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Q. Air at 25 degree Celsius flows over a flat surface with a sharp leading edge at 1.5 m/s. Find the value of Reynolds number. For air at 25 degree Celsius, kinematic viscosity = 15.53* 10n¯⁶ m²/s

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