Effect of distance between 90 degrees elbow close to upstream of orifice plate and the orifice plate on discharge coefficient

The effect of distance between 90 degrees elbow close to the upstream face of an orifice plate and the orifice plate on discharge coefficient was investigated. The distribution of discharge coefficient and differential pressure caused by elbow and short upstream straight length were examined and a modified discharge coefficient was introduced. The results presented in this study could be useful when the orifice plate is installed under the condition of simple flow disturbance element and short upstream straight length