The angle of repose has been used in many branches of science to show the flow properties of solids. The angle of repose is a characteristic related to the resistance or friction between particles to motion between particles. The results of the slope angle test are very dependent on the method used. Due to the segregation and consolidation of the materials, experimental difficulties arise or the aeration of the powder takes the shape of a cone.
The angle of repose formula.
The slope angle is specified by θ.
It is expressed by Tan θ = µ = h/r.
Where,
h is the height,
r= stack radius
and µ is the coefficient of friction.