Experimental Study On Hydraulic Properties Of Porous Hoses

The porous hose has a wide range of applications; it has been used in many varied areas. The perforated flexible conduit, which has been studied in this thesis, is a kind of the porous hose; evenly distribution is its familiar role. For a perforated flexible conduit, the degree of its good and bad often judge by the level of evenly distribution. After theoretical analysis, we find that if we want to have a perforated flexible conduit which has much better level of evenly distribution, we must make it has better level of evenly distribution of pressure. So how to make the perforated flexible conduit has better level of evenly distribution of pressure has been the main aim of the study in this thesis.This thesis takes pressure distribution rule of the perforated flexible conduit as a starting point, and focus on studying the length of the hose, the imported pressure head, the diameter of hose, drop-distance and laying of pipelines slope which are primary factors affecting the evenly distribution of pressure. At the same time, experimental study of the pressure distribution rule, the current capacity distribution rule and flowed the uniformity change rule are made, and emphatically focusing on the theoretical study of the pressure distribution rule. Final, we come to some conclusions:After the theoretical study to pressure distribution rule of the porous hose, according to the law of momentum, in condition of the laying only one slope along the porous hose, the variable mass of momentum equation had been established. The pressure formula of random point of the perforated flexible conduit has been given. The formula of the head losses along the porous hose are demonstrated through the infinitesimal method.The regularity for change of single-hole flow, single-hole flow average have been obtained, when the porous hose is influenced by the hose length, the calibre, the pitch of holes, the hose pressure head and the laying slope. When the hose pressure head or the laying slope enhance, the single-hole flow will increase. There is a negative correlation between the single-hole flow and the open ratio. With the increasing of the hose pressure head, the laying slope or the pitch of holes, the single-hole flow average of the porous hose will increase, the incremental amount will reduce besides these.The regularity for change of the flow uniformity of the porous hose have been obtained, when the porous hose is influenced by the hose length, the pitch of holes, the hose pressure head and the laying slope. At the same time, the method how to improve the flow uniformity of the porous hose has been brought forward. With the increasing of the hose pressure head or the pitch of holes, the flow uniformity of the porous hose will increase. But when the laying slope is greater than change rate of the head losses along the porous hose, the flow uniformity of the porous hose will reduce. Otherwise the flow uniformity of the porous hose will increase. With the increasing of the hose length, the flow uniformity of the porous hose will reduce.