Siphon Spillway

Citation

Gramatky, Ferdinand Gunner and Robinson, Kenneth Hall (1929) Siphon Spillway. Master's thesis, California Institute of Technology. doi:10.7907/972C-WG13. https://resolver.caltech.edu/CaltechETD:etd-02252005-160805

Abstract

A brief summary of conclusions drawn from this work is as follows:

1. The coefficient of discharge increases directly as the operating head on a siphon spillway while discharging into deep water, and decreases rapidly with increase of head when discharge is in shallow water and air.

The rate of discharge increases with the head, and approaches a nearly constant value for higher heads.

Similar tests made on the model without the air trap seal has the effect of increasing the rate of discharge when discharging into air, and a slight increase of the coefficient of discharge at lower heads.

2. Better means of measuring pressure must be sought, and until then, accurate means of obtaining losses from point to point are not available. A Pitot tube exploration seems the best suggestion. The maximum losses are in the entrance, throat, and bend over the crest. Q = AV does not hold for ordinary piezometer tube measurements, and Bernoulli's theorem may not be applied.

3. The principles of similitude my be applied to the siphon, and the scale factor may be increased to 4, with all characteristics remaining the same. The discharge varies as the five halves power of the scale factor.

Thesis Files