Relations for depth and velocity and specific energy in control sections of open channels flow

• Autorzy: Kubrak Janusz , Kubrak Elżbieta , Kozioł Adam , Krukowski Marcin

Identyfikatory

DOI

10.5604/01.3001.0055.2038

• Języki publikacji: EN

Abstrakty

EN

In practical open channel hydraulics, critical flow relationships play a crucial role in understanding and analyzing flow conditions. The critical depth for a given cross section for a constant flow rate is calculated on the basis of the specific energy concept, which was first introduced by Bakhmeteff in 1912. The section in the water channel where critical flow occurs and the subcritical flow passes into supercritical flow is often used in hydraulic calculations as the control section. The article presents some practical aspects and considerations related to the relationships between depth, velocity head, and specific energy for critical flow in typical cross-sections of open channels, as well as the dependence of these elements in rectangular, triangular, trapezoidal, power-law and circular crosssections of channels. In the case of rectangular cross sections, asymmetric triangular cross sections or cross sections described by a power function, it is necessary to prove that there are constant algebraic relations, independent of the flow rate, for the critical depth. In trapezoidal, circular, or natural cross sections, for which there are no explicit dependencies for the critical depth, the calculated values of relationship between the critical depth, the height of the critical velocity and the energy head are not constant and tend to vary with the width of the cross-section and the flow rate. The article presents characteristic values between the critical depth, the height of the critical velocity, and the energy head for trapezoidal and circular cross sections.

Słowa kluczowe

EN

open channel flow; specific energy; critical depth; critical velocity

• Wydawca: Szkoła Główna Służby Pożarniczej
• Czasopismo: Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej
• Rocznik: 2025
• Tom: Nr 95 (tom 1)
• Strony: 7--21
• Opis fizyczny: Bibliogr. 13 poz., rys., tab.

Twórcy

autor

Kubrak Janusz

• Warsaw University of Life Sciences, Institute of Environmental Engineering, Warsaw, Poland

• https://orcid.org/0000-0001-7322-4951

autor

Kubrak Elżbieta

• Warsaw University of Life Sciences, Institute of Environmental Engineering, Warsaw, Poland

• https://orcid.org/0000-0001-5318-2256

autor

Kozioł Adam

• Warsaw University of Life Sciences, Institute of Environmental Engineering, Warsaw, Poland

• https://orcid.org/0000-0002-4059-8639

autor

Krukowski Marcin

• Warsaw University of Life Sciences, Institute of Environmental Engineering, Warsaw, Poland

• https://orcid.org/0000-0002-4010-7916

Bibliografia

• [1] Aiyesimoju, K.O., (2010). Universal specific energy curve for parabolic open channels. J. Sci. Technol. (Ghana), 30 (1), pp. 151–157.
• [2] Bakhmeteff, B.A., (1912). O neravnomernom dwijenii jidkosti v otkrytom rusle (Varied Flow in Open Channel). St Petersburg, Russia (in Russian).
• [3] Bakhmeteff, B.A., (1932). Hydraulics of open channels, 1st Ed., New York: McGraw–Hill.
• [4] Bélanger, J.B., (1828). Essai sur la solution numérique de quelques problèmes relatifs au mouvement permanent des eaux courantes (Essay on the numerical solution of some problems relative to steady flow of water). Carilian-Goeury, Paris (in French).
• [5] Bélanger, J.B., (1849). Notes sur le Cours d’Hydraulique. (Notes on the Hydraulics Subject). Mém. Ecole Nat. Ponts et Chaussées (Paris, France) (in French).
• [6] Bos, M.G. (1976). Discharge measurement structures. 161. Ilri.
• [7] Chanson, H., (2004). The hydraulics of open channel flows: An introduction, 2nd Ed., Oxford, U.K.: Butterworth-Heinemann.
• [8] Chow, V.-T., (1959). Open channel hydraulics. New York: McGraw-Hill.
• [9] Henderson, F.M., (1966). Open channel flow. New York: The MacMillan Comp.
• [10] Houghtalen, R.J., Akan, A.O., and N.H.C. Hwang, (2010). Fundamentals of hydraulic engineering systems. Edition 4. Pearson Education.
• [11] Rouse, H., (1946). Elementary Mechanics of Fluids. Inc., New York: Dover Publications.
• [12] Streeter, V.L., (1971). Fluid mechanics. New York: McGraw-Hill.
• [13] Subramanya, K., (2015). Flow in open channels. New Delhi: McGraw Hill Education (India) Private Limited.