Heat Transfer through a Boundary Layer

Though the burning rate of a propellant is represented by Eq. (3.68) at constant pressure, Eq. (3.68) is no longer valid when a cross-flow is applied to the burning propellant The heat flux transferred from the cross-flow to the burning surface of 

In a number of experimental studies, the heat-transfer coefficient with cross-flow, h, is determined according to 

If one assumes that the increased burning rate, r, caused by the cross-flow is attributable to the heat flux through the boundary layer, the overall burning rate of the energetic material, r, is given by 

This burning rate equation with cross-flow is derived on the basis of experimental data and is known as the Lenoir-Robilard equation.I l 

Though erosive burning is highly dependent on the cross-flow velocity, the physical structure of the propellant also plays a dominant role in determining the erosive 

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