Calculation of steady flow pressure loss coefficients for pipe junctions

Pipe junctions are found in many engineering systems. It is often desirable to predict the pressures within such systems. Steady flow pressure loss coefficients can be defined that attempt to characterize the effects of the junction on the flow. These coefficients are usually established experimentally, but empirical and analytical expressions exist that allow some of the loss coefficients for junctions to be calculated. In the paper, simple expressions are presented that allow all of the loss coefficients for a three pipe T-junction, with any lateral branch angle or area ratio, to be calculated. The coefficients obtained using these expressions are compared with measured values. The steady flow pressure loss coefficients calculated in this way have been applied to the simulation of the propagation of a shock wave through a T-junction. Predictions of the mean pressure levels show good correlation with measurements.