# What is the ratio of momentum thickness to the boundary layer thickness?

## What is the ratio of momentum thickness to the boundary layer thickness?

What is the ratio of momentum thickness to the boundary layer thickness δ when the layer velocity profile is given by u U ∞ = ( y δ ) 1 / 2 Where u is velocity at height y above surface and is free stream velocity of flow.

**What is the displacement thickness of a boundary layer?**

The distance to the point where vV=0.99 . Distance where the velocity ‘v’ is equal to the shear velocity V’, that is,where v = V. The distance by which the main flow is to be shifted from the boundary to maintain the continuity equation.

### What is the ratio of displacement thickness to nominal thickness for a linear distribution of velocity in the boundary layer on a flat plate 1 point?

∴ After simplification, the answer will be 1/2.

**What do you mean by displacement thickness?**

Displacement thickness is basically defined as the distance, measured perpendicular to the boundary of the solid body, by which the boundary should be displaced to compensate for the reduction in flow rate on account of boundary layer formation. Displacement thickness will be displayed by the symbol δ*.

#### How is the displacement thickness in boundary layer analysis defined Mcq?

Explanation: The thickness of the boundary layer represented by δ is arbitrarily defined as that distance from the boundary surface in which the velocity reaches 99% of the velocity of the mainstream.

**What is displacement thickness in fluid mechanics?**

The displacement thickness for the boundary layer is defined as the distance the surface would have to move in the y-direction to reduce the flow passing by a volume equivalent to the real effect of the boundary layer.

## What is the momentum thickness for the boundary layer with velocity distribution?

For a known boundary-layer stream-wise velocity profile, u(x,y), at downstream distance x, this thickness is defined by: u(x,δ99) = 0.99Ue(x).

**What is momentum thickness in boundary layer theory?**

Momentum Thickness (θ) Momentum thickness is defined in relation to the momentum flow rate within the boundary layer. This rate is less than the rate that would occur if no boundary layer existed, when the velocity in the vicinity of the surface, at the station considered, would be equal to the mainstream velocity Ue.