| In recent years,with the rapid development of our country and hydropower construction of high dam is increasing,the impact on downstream water ecological environment of the high dam operation also gradually attention.High head drainage buildings due to the high water head,large flow,water flow has a larger kinetic energy,the flow of the severe turbulence can make water mixing ambient air,dissolved gas downstream water super saturation problem.Past the research of dam downstream super saturation of dissolved gases,many to 50 m below the dam,the research of high dam,the water dissolved gas super saturation phenomenon can make the aquatic organisms living environment is destroyed,original serious when even led to the deaths of aquatic organisms,in guarantee under the premise of building their own safety,for how to reduce the downstream water dissolved gas concentration,dissolved gas super saturation solution requires more in-depth research.The step + bottom flow dissipation can work as a combined elimination method,and its elimination will be better.Ladder + underflow energy dissipation work,since the ladder section water drainage to the stilling basin,and the pool water turbulence,entrainment,surrounding air aeration water flow,water flow aeration can cause of total dissolved gas in water production of super saturation problem,through research and analysis steps + bottom flow energy dissipation work flow within different stilling basin structure zone aeration concentration distribution rule and gas diffusion mechanism,in order to reduce water dissolved gas in super saturation phenomenon occurrence,protection of river water ecology and water environment security theory basis.Ladder + bottom flow energy dissipation work flow within different stilling basin structure zone by discharge flow aeration concentration distribution,spillway slope height,step size and form,the tail hom,flow velocity,mixed gas,the influence of such factors as local temperature and pressure.In this paper,by constructing a ladder + bottom flow energy dissipation work model,adopt hydraulic test method,the ladder + stilling basin for the underflow energy dissipation work flow water flow structure inside partitions,with no increase forced aeration and mixing gas,under the condition of two kinds of change discharge flow respectively,tail height,the measured velocity of different flow structure in stilling basin area,floor structure along the time average pressure and different water area,the mixed gas density,get their distribution curve,analysis of different hydraulic conditions on the structure of speed in the pool water,when all the pressure and the influence of mixed gas concentration distribution rules. |
