HYDRAULICS. ENGINEERING HYDROLOGY. HYDRAULIC ENGINEERING

Hydraulic resistancein channels having rough bottoms

Vestnik MGSU 9/2013
  • Medzveliya Manana Levanovna - Moscow State University of Civil Engineering (MGSU) Candidate of Technical Sciences, Associate Professor, Department of Hydraulic Engineering, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Pipiya Valeriy Valerianovich - Breesize Trading Limited Candidate of Technical Sciences, Senior Project Engineer, Breesize Trading Limited, 42 Mosfil’movskaya St., Moscow, 119285, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 95-100

The authors study the dependence of the hydraulic friction coefficient on the Froude number for open steady uniform flows in channels having a high relative roughness. In the article, the authors provide the equation, which describes the hydraulic resistance in open channels having rough bottoms.Experiments were conducted in the rectangular tray (6,000×100×200 mm). Metal balls having the diameter of 15.1 mm were used to simulate uniform roughness. Aqueous solutions of glycerol were added as operating fluids. Average roughness was identified as k = 0.8d. The range of values of the main factors was as follows: inclination 0.011 —0.06; the Froude number 0.13 — 6.02; relative smoothness 0.3 — 1.36. The authors have proven that the value of the coefficient of hydraulic friction in the zone of the laminar flow is not dependent on the Froude number.The influence of the Froude number on the hydraulic friction is manifested in the areas of the turbulent flow.

DOI: 10.22227/1997-0935.2013.9.95-100

References
  1. Zegzhda A.P. Gidravlicheskie poteri na trenie v kanalakh i truboprovodakh [Hydraulic Friction Losses in Channels and Pipelines]. Moscow, 1967, 282 p.
  2. Reinius R. Steady Uniform Flow in Open Channel. Stokholm, Tekniska Hogskola, no. 5. Handlinger Sweden. 1961, 179, pp. 3—46.
  3. Homma M. Fluid Resistance in Water Flow of High Froud Number. Proc. and Japan Nat. Congr. Appl. Mech. 1952, Sci. Council, Japan, Tokyo, 1953, pp. 251—254.
  4. Kirschmer O. Reibungsverluste in Rohren und Kanalen. Gas- und Wasserfach. 1966, vol. 107, no. 50, pp. 1405—1416.
  5. Rouse H., Koloseus. The Role of Froude Number in Open Channel Resistance. Hydr. Research. IANR. Holland. 1963, vol.1, no. 1.
  6. Rouse H. Critical Analysis of Open Channel Resistance. J. Hydr. Div. Proc. ASCE. 1965, no. 4, 91, part 1, pp. 1—25.
  7. Al'tshul' A.D. Gidravlicheskie soprotivleniya [Hydraulic Resistances]. Moscow, Nedra Publ., 1982, 223 p.
  8. Al'tshul' A.D., Lyapin V.Yu., Al'kheder B. O vliyanii formy secheniya rusla na gidrodinamicheskie kharakteristiki turbulentnykh potokov [On the Influence of the Shape of the Channel Section on Hydro-dynamic Characteristics of Turbulent Flows]. Izvestiya vuzov. Energetika [News of Institutions of Higher Education. Power Engineering]. 1992, no. 4, pp. 91—94.
  9. Medzveliya M.L., Pipiya V.V. Faktory, vliyayushchie na koeffitsient gidravlicheskogo treniya ravnomernykh otkrytykh potokov [Factors of Influence on the Coefficient of Hydraulic Friction for Open Uniform Flows]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2011, no. 8, pp. 398—402.
  10. Al'tshul' A.D. Gazogidravlicheskaya analogiya N.E. Zhukovskogo i ee znachenie dlya gidrotekhniki [N.E. Zhukovskiy’s Gas-hydraulic Analogy and Its Significance for Hydraulic Engineering]. Gidrotekhnicheskoe stroitel'stvo [Hydraulic Engineering Construction]. 1948, no. 8, pp. 14—19.
  11. Poltavtsev V.I., Efremov V.I. Ob osobennostyakh gidravlicheskogo soprotivleniya otkrytykh potokov pri bol'shoy sherokhovatosti rusla [On Features of Hydraulic Resistance of Open Flows in Case of High Roughness of the Channel]. Trudy LGMI [Works of the Leningrad Institute of Hydrometeorology]. 1967, no. 25, pp. 5—12.

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Dependence of the critical Froude number on the hydraulic friction number

Vestnik MGSU 10/2013
  • Medzveliya Manana Levanovna - Moscow State University of Civil Engineering (MGSU) Candidate of Technical Sciences, Associate Professor, Department of Hydraulic Engineering, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .
  • Pipiya Valeriy Valerianovich - Breesize Trading Limited Candidate of Technical Sciences, Senior Project Engineer, Breesize Trading Limited, 42 Mosfil’movskaya St., Moscow, 119285, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 203-233

The article considers the critical Froude number dependent on the hydraulic friction number in open channels with high relative roughness, which is comparable with the depth of the stream.The author offers an equation, which presents the critical value of Froude number and shows that the value of critical Froude number decreases with the increasing in relative roughness.Experiments were made in the rectangular channel. Steady roughness was created by metal balls.The critical value of Froude number usually taken as 1, no matter if the flow changes(furious or tranquil).The article shows, that the critical value of Froude number is not constant and equal to 1, but it decreases with the increasing of the pipe friction number in channels with high relative roughness.

DOI: 10.22227/1997-0935.2013.10.203-233

References
  1. Zegzhda A.P. Gidravlicheskie poteri na trenie v kanalakh i truboprovodakh [Hydraulic Friction Losses as a Result of Frictions in Channels and Pipelines]. Moscow, 1967, 282 p.
  2. Reinus E. Steady Uniform Flow in Open Channels Transactions. Stockholm, Tekniska Hogskola, 1961, no. 179, pp. 3—46.
  3. Homma M. Fluid Resistance in Water Flow of High Froude Number. Proc. And Japan Nat. Congr. Appl. Mech. 1952, Sci. Council Japan, Tokyo, 1953, pp. 251—254.
  4. Rouse H., Koloseus H.J., Davidian J. The Role of Froude Number in Open-Channel Resistance. Journal of Hydraulic Research. Holland, 1963, vol. 1, no. 1, pp. 14—19.
  5. Rouse H. Critical Analysis of Open-Channel Resistance. Journal of the Hydraulics Division. ASCE, 1965, vol. 91, no. HY4, pp. 1—25.
  6. Al'tshul' A.D. Gidravlicheskie soprotivleniya [Hydraulic Resistances]. Moscow, Nedra Publ., 1982, 223 p.
  7. Poltavcev V.I., Efremov V.I. Ob osobennostyakh gidravlicheskogo soprotivleniya otkrytykh potokov pri bol'shoy sherokhovatosti rusla [On Features of Hydraulic Resistance of Open Flows in Case of High Roughness of the Channel]. Trudy LGMI [Works of the Leningrad Institute of Hydrometeorology]. 1967, no. 25, pp. 5—12.
  8. Medzveliya M.L., Pipiya V.V. Faktory, vliyayushchie na koeffitsient Gidravlicheskogo treniya ravnomernykh otkrytykh potokov [Factors of Influence on the Coefficient of Hydraulic Friction for Open Uniform Flows]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2011, no. 8, pp. 398—402.
  9. Medzveliya M.L., Pipiya V.V. Gidravlicheskoe soprotivlenie lotkov s sherokhovatym dnom Medzvelija [Hydraulic Resistance in Channels Having Rough Bottoms]. Vestnik MGSU [Proceedings of Moscow State University of Civil Engineering]. 2013, no. 9, pp. 95—100.
  10. Al'tshul' A.D., Pulyaevskiy A.M. O gidravlicheskikh soprotivleniyakh v ruslakh s usilennoy sherokhovatost'yu [On the Problem of Hydraulic Resistance in Channels Having High Roughness]. Gidrotekhnicheskoe stroitel'stvo [Hydraulic Engineering]. 1774, ¹ 7, pp. 27—29.

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