Boundary Layer

Air (density = 1.2 kg/m 3 , kinematic viscosity = 1.5 × 10 -5 m 2 /s) flows over a flat plate with a free-stream velocity of 2 m/s. The wall shear stress at a location 15 mm from the leading edge is τ w . What is the wal...

A solid spherical bead of lead (uniform density = 11000 kg/m 3 ) of diameter d = 0.1 mm sinks with a constant velocity V in a large stagnant pool of a liquid (dynamic viscosity = 1.1 × 10 -3 kg∙m -1 ∙s -1 ). The coeffici...

The velocity profile inside the boundary layer for flow over a flat plate is given as $${u \over {{U_\infty }}} = \sin \left( {{\pi \over 2}\,{y \over \delta }} \right),$$ where $${U_\infty }$$ is the free stream velocit...

Consider a laminar flow at zero over a flat plate . The shear stress at the wall is denoted by $${\tau _w}.$$ The axial positions $${x_1}$$ and $${x_2}$$ on the plate are measured from the leading edge in the direction o...

The instantaneous stream-wise velocity of a turbulent flow is given as follows: $$$u\left( {x,y,z,t} \right) = \overline u \left( {x,y,z} \right) + \mu '\left( {x,y,z,t} \right)$$$ The time - average of the fluctuating v...

The Blasius equation related to boundary layer theory is a

Air ( $${\rho = 1.2\,\,kg/{m^3}}$$ and kinematic viscosity, $${v = 2 \times {{10}^{ - 5}}{m^2}/s}$$ ) with a velocity of $$2m/s$$ flows over the top surface of a flat plate of length $$2.5m.$$ If the average value of fri...

Consider laminar flow of water over a flat plate of length $$1$$ $$m.$$ If the boundary layer thickness at a distance of $$0.25$$ $$m$$ from the leading edge of the plate is $$8$$ $$mm,$$ the boundary layer thickness (in...

An incompressible fluid flows over a flat plate with zero pressure gradient. The boundary layer thickness is $$1mm$$ at a location where the Reynolds number is $$1000$$. If the velocity of the fluid alone is increased by...

Consider an incompressible laminar boundary layer flow over a flat plate of length $$L$$, aligned with the direction of an incoming uniform free stream. If $$F$$ is the ratio of the drag force on the front half of the pl...

For air flow over a flat plate, velocity $$(U)$$ and boundary layer thickness $$\left( \delta \right)$$ can be expressed respectively, as $$${U \over {{U_\infty }}} = {3 \over 2}{y \over \delta } - {1 \over 2}{\left( {{y...

Flow separation in flow past a solid object is caused by

If $$'x'$$ is the distance measured from the leading edge of a flat plate, then laminar boundary layer thickness varies as

The necessary and sufficient condition which brings about separation of boundary layer is $${{dP} \over {dx}} > 0$$

As the transition from laminar to turbulent flow is induced in a cross flow past a circular cylinder the value of the drag coefficient drops.

The predominant forces acting on an element of fluid in the boundary layer over a flat plate in a uniform parallel stream are:

A streamlined body is defined as a body about which