Theoretical computation of air flow through air vent for hydropower intakes

摘要

A. Theoretical method for computing the air flow through the isolated air vent for the hydropower intakes was presented . It considered not only the characteristics of air flow, including especially the compressibility of air, but also the friction losses in the vent as well as the effect of the variation of air pressure above the water surface in the penstock.B. The method present in this paper can compute not only the maximum discharge of the air flow, but also the relationship of the air flow Q_a = Q_a (t) which tells us the instant ofoccurring of the maximum air discharge and the duration of high discharge of air flow, and thereby made an reliable basis for studying the appropriate value of allowable wind speed from the viewpoint of noise control.