A.與流程長(zhǎng)度成正比,與壁面切應(yīng)力和水力半徑成反比 B.與流程長(zhǎng)度和壁面切應(yīng)力成正比,與水力半徑成反比 C.與水力半徑成正比,與流程長(zhǎng)度和壁面切應(yīng)力成反比 D.與壁面切應(yīng)力成正比,與流程長(zhǎng)度和水力半徑成反比
如圖所示,設(shè)水在閘門下流過(guò)的流量Q=4.24m3/s,門前斷面1的總水壓力為P1=19.6kN,門后斷面2的總水壓力為P2=3.13kN,閘門前、后的斷面平均流速分別為v1=2.12m/s,v2=5.29m/s,不計(jì)水頭損失和摩擦阻力,則作用于單位寬度(1m)上閘門的推力F為:()
A.2506N B.3517N C.2938N D.3029N
圖示射流流量Q=100L/s,出口流速v=20m/s,不計(jì)水頭損失和摩擦阻力,則水射流對(duì)垂直壁面的沖力Fx為:()
A.1600N B.2×106N C.2000N D.2×105N