坝体泄洪深孔明槽段体型研究

通过对三峡泄洪深孔明槽段体型试验研究 ,比较了明槽段不同抛物线型的压力特性和空化特性 ,并提出了明槽段陡槽方案。研究结果表明 :陡槽方案较之抛物线方案 ,压力特性和水流空化特性有显著改善。陡槽方案是免空化的 ,而抛物线方案较难达到免除空化 ;并且陡槽方案对有压段压力及空化特性 ,以及泄流能力均没有影响。因此 ,对于高速水流条件下的明槽段体型 ,陡槽方案是一种较为适宜的布置形式。

Study on configuration of open channel of flood-releasing deep outlet

Through model test of TGP's flood releasing deep outlet,the characteristics of pressure distribution and cavitation are compared among different types of parabolic profile,and a chute type is put forward.The research results indicate that,in comparison with the parabolic type,the chute type's pressure and cavitation characteristics are evidently improved.The chute type is cavitation free,but the parabolic type is difficult to avoid cavitation.The chute scheme doesn't induce any negative influences to the discharge capacity and characteristics of pressure and cavitation in the outlet's pressure section.Therefore,the chute type is a feasible type for the open channel under high velocity flow.