Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 2005

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: channels discharge capacity

Sortuj według:

Ogranicz wyniki do:

Określenie współczynników oporu w korycie rzeki nizinnej

Świątek D., Kubrak J., Pachuta K.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

2005

Vol. 14, No. 2

161--166

Calculation methods of discharge capacity in rivers and channels with flexible vegetation are based at the Manning’s and Darcy-Weisbach’s friction factors to appear local river bed stresses coupled with other fluid dynamic processes. An example of friction factors calculation has been developed in this paper. The hydrometrical measurement has been surveyred in a selected cross section in the Lower Biebrza basin. The absolute roughness for the divided parts of cross sections has been calculated by using Collebrook-White’s equation. Results show that friction factors for the vegetation boundary are much greater then for the bottom of cross sections.

O obliczaniu przepustowości koryt rzecznych

Kubrak E.

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

2005

Vol. 14, No. 1

29--38

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.