O obliczaniu przepustowości koryt rzecznych

The calculation method of discharges capacity in rivers and channels are based on the Manning-Stricklera and Darcy-Weisbach friction factors to represent local river bed stresses coupled with other fluid dynamic processes. This paper describes the comparison of the velocities computed with the use of both methods of the evaluation of friction factors. The velocities calculated within rough zone based on Manning-Strickler and Darcy-Weisbach friction factors agree with each other for relative roughness k/4R(0.001; 0.050 ). When the relative roughness goes beyond this rangę or the flow is within smooth or transition zones, the velocities calculated on the basis of Manninga-Strickler friction factor are greater by about 20%. In rough zone there are two areas on Moody Diagram in which the ratio vST/v changes with the depth of the channel. In the transition zone the difference between the calculated velocities based on two methods inerease with the depth of the channel.