Table of Contents
What is the characteristic length of an airfoil?
In simple terms, a characteristic length is THE MOST important length scale in a fluid flow. For example: (1) In a VERY LONG pipe or channel flow, the characteristic length is diameter or channel width – By very long, I meant the velocity becomes independent of the pipe length.
What can be used as a characteristic length for Reynolds number?
Airfoil chord is usually used as characteristic length in Reynolds number calculation.
How is Reynolds number for airfoil calculated?
Flow around airfoils Fluid dynamicists define the chord Reynolds number R like this: R = Vcν, where V is the flight speed, c is the chord length, and ν is the kinematic viscosity of the fluid in which the airfoil operates, which is 1.460×10−5 m2/s for the atmosphere at sea level.
What is Reynolds number airfoil?
The Reynolds number is a dimensionless value that measures the ratio of inertial forces to viscous forces and descibes the degree of laminar or turbulent flow. Systems that operate at the same Reynolds number will have the same flow characteristics even if the fluid, speed and characteristic lengths vary.
What is a characteristic length scale?
In physics, a characteristic length is an important dimension that defines the scale of a physical system. In computational mechanics, a characteristic length is defined to force localization of a stress softening constitutive equation. The length is associated with an integration point.
What is characteristic linear dimension Reynolds number?
The Reynolds number represents the ratio of inertial forces to viscous forces and is a convenient parameter for predicting if a flow condition will be laminar or turbulent. It is defined as a characteristic length multiplied by a characteristic velocity and divided by the kinematic viscosity.
What is characteristic chamber length?
The characteristic chamber length is defined as the length of a rocket of the same volume would have if it were a straight tube and had no converging section… (He then shows the same equation you do in the question). Here the chamber is considered to include all the volume up to the throat area….
How do you calculate Reynolds number of an aircraft?
The Reynolds number Re then becomes:
- Re = (r * V * dV/dx) / (mu * d^2V/dx^2) The gradient of the velocity is proportional to the velocity divided by a length scale L.
- Re = (r * V * V/L) / (mu * V / L^2) Re = (r * V * L) / mu.
- nu = mu / r. Re = V * L / nu.
What is characteristic length formula?
In computational mechanics, a characteristic length is defined to force localization of a stress softening constitutive equation. The length is associated with an integration point. For 2D analysis, it is calculated by taking the square root of the area.