ON THE COMPRESSIBLE FLOW-THROUGH AN ORIFICE

A new theory for the compressible flow through an orifice is presented which provides a significant advance over the approach currently empl oyed. As the flow approaches the critical regime (local sonic conditio n), measurements diverge from the theoretical result due to the non-on e-dimensionality of the flow. Nevertheless, a straight forward correla tion is available, and the measurements for different pipe/orifice geo metries all appear to lie in the vicinity of a single, universal curve . As the flow approaches the incompressible condition the correlation factor (the discharge coefficient) becomes unity.