Open Channel Flow Closed pipe • Pump or fan driving force • No free surface Open channel • Gravity driving force • Free surface
Open Channel Flow
Closed pipe• Pump or fan driving force• No free surface Open channel• Gravity driving force• Free surface
Open channel
Prismatic channel Hydraulic radius• Rh = flow area/wetted perimeter
• Optimize for greatest flow at smallest wetted perimeter
Manning equation
USCS: cfs Q = (1.49/n)A Rh
2/3So1/2
Manning coefficient: n depends on channel surface smoothness
Part 1
Flow valve wide open; allow flow to stabilize
Record flow meter value Record dimensions for Manning equation Install rectangular weir; obtain dimensions Install v-notch weir; obtain dimensions