A Dissertation submitted in partial fulfilment of the requirement for the Degree of Doctor of Engineering, School of Engineering and Technology

Thesis (Ph.D.) - Asian Institute of Technology, 1981

General equations are derived for shallow- flow over a two-dimensionally curved bed; the Saint-Venant and the recent Dressler equations are recovered as special cases. The concept of Froude number is generalised, and the validity of the Dressler equations discussed. The Dressler equations are solved for steady flow, including transition profiles. Application of these equations to a tested spillway crest reproduces its head-discharge relationship and the pressure distribution in remarkable agreement with the experimental data. Predictions for a spillway toe also compare with earlier theory and experiment. Finally, new experiments were carried out for steady flow over a symmetric and an unsymmetrical profile ,and the Dressler equations are found to be applicable in the range -2 < Kh < 0.54 (K denotes bed curvature, denotes the flow depth normal to the bed) for steady frictionless flow over curved beds. Roll waves in curved bed open channel s and formal extension of the Dressler equations to higher order are briefly discussed in appendices.