Pipe junctions are found in many engineering systems. It is often desirable
to predict the pressures within such systems. Steady flow pressure loss co
efficients can be defined that attempt to characterize the effects of the j
unction on the flow. These coefficients are usually established experimenta
lly, but empirical and analytical expressions exist that allow some of the
loss coefficients for junctions to be calculated. In the paper, simple expr
essions are presented that allow all of the loss coefficients for a three p
ipe T-junction, with any lateral branch angle or area ratio, to be calculat
ed. The coefficients obtained using these expressions are compared with mea
sured 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 co
rrelation with measurements.