Flow Calculator is calculator of open channel flow. App calculates Manning equation for different channel shapes (user can choose different parameters of equation to be calculated). App supports rectangular, trapezoidal, triangular and circular channel shape.

App also contains short theory behind Manning equation and table with values of all Manning coefficients. Manning equation is empirical equation estimating open channel flow:

v = 1/n*R^(2/3)*S^(1/2)

where:

v...cross section average velocity (m/s)
n...Manning coefficient
R...hydraulic radius (m)
S...slope of water surface (m/m)

User can choose different parameters to be calculated for open channel flow:

RECTANGULAR CHANNEL
- velocity(v) & discharge(Q)
- channel slope(S) from velocity(v)
- channel slope(S) from discharge(Q)
- manning coefficient(n) from velocity(v)
- manning coefficient(n) from discharge(Q)
- water depth(h) from discharge(Q)

TRAPEZOIDAL CHANNEL
- velocity(v) & discharge(Q)
- channel slope(S) from velocity(v)
- channel slope(S) from discharge(Q)
- manning coefficient(n) from velocity(v)
- manning coefficient(n) from discharge(Q)
- water depth(h) from discharge(Q)
- bank slope(m) from discharge(Q)

TRIANGULAR CHANNEL
- velocity(v) & discharge(Q)
- channel slope(S) from velocity(v)
- channel slope(S) from discharge(Q)
- manning coefficient(n) from velocity(v)
- manning coefficient(n) from discharge(Q)
- water depth(h) from discharge(Q)
- bank slope(m) from discharge(Q)

CIRCULAR CHANNEL
- velocity(v) & discharge(Q)
- channel slope(S) from velocity(v)
- channel slope(S) from discharge(Q)
- manning coefficient(n) from velocity(v)
- manning coefficient(n) from discharge(Q)
- water depth(h) from discharge(Q)