Effect of roughness on flow measurements in sloping rectangular channels with free overfall

Fırat, Can Ersen
The characteristics of the subcritical, critical and supercritical flows at the rectangular free overfall were studied experimentally to obtain a relation between the brink depth and the flow rate. A series of experiments were conducted in a tilting flume with wide range of flow rate and two bed roughness in order to find the relationship between the brink depth, normal depth, channel bed slope and bed roughnesses. An equation was proposed to calculate the flow rate if only the brink depth, roughness, and channel bed slope are known. An alternate iterative solution was offered to calculate discharges if the brink depth and uniform flow depth are known.


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Özkan, H. (Informa UK Limited, 1987-2)
The effect of thermal neutron irradiation due to the B10(n, α)Li7 reaction on the elastic wave velocities and the elastic moduli of tourmaline crystals has been studied. Oriented tourmaline samples have been irradiated with thermal neutrons to 7.6 × 1018n/cm2 and the elastic wave velocities determined by ultrasonic measurements. The elastic wave velocities are not affected by thermal neutron irradiation below 8 × 10l7n/cm2, effects starting to appear at approximately 1 × l018n/cm2 with more important decrea...
The behaviour of flow in the immediate vicinity of a sloping rectangular channel with free overfall
Kutlu, İhsan; Tiğrek, Şahnaz; Department of Civil Engineering (2005)
The flow characteristics of the subcritical and supercritical flows over a free overfall in a rectangular channel are studied experimentally. A series of experiments were conducted in a tilting flume with a wide range of flow rate. Data collected by several researchers are also included. An empirical relationship, which gives the flow rate as a function of the brink depth, the channel bed slope and the bed roughness are confirmed by using data collected in present study. In addition, the behaviors of the ra...
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Ömürlü, Çiğdem; Özbayoğlu, Evren; Department of Petroleum and Natural Gas Engineering (2006)
The primary objective of this study is to understand the mechanism, the hydraulics and the characteristics, of the two-phase flow in horizontal annuli. While achieving this goal, both theoretical and experimental works have been conducted extensively. The METU-PETE-CTMFL (Middle East Technical University, Petroleum and Natural Gas Engineering Department, Cuttings Transport and Multiphase Flow Laboratory) multiphase flow loop consists of 4.84 m long eccentric horizontal acrylic pipes having 0.1143m inner dia...
Effect of Gas Diffusion Layer Characteristics and Addition of Pore-Forming Agents on the Performance of Polymer Electrolyte Membrane Fuel Cells
Senguel, Erce; Erkan, Serdar; Eroğlu, İnci; BAÇ, NURCAN (Informa UK Limited, 2009-01-01)
The performance of five layer membrane electrode assemblies having different characteristics of gas diffusion layers was determined at 70 degrees C cell temperature and ambient pressure. The maximum power density at 0.6 V was 0.36 W/cm(2) for the membrane electrode assembly prepared with the gas diffusion layer having minimum thickness (SGL BC 30 type). On the other hand, the maximum power density at 0.5 V was 0.44 W/cm(2) for the membrane electrode assembly prepared with SGL BC 34 type gas diffusion layer....
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Based on Tresca's yield criterion and the flow rule associated with it, the distribution of stress and strain in a linearly strain hardening elastic-plastic hollow shaft subject to monotonously increasing angular speed and a negative radial temperature gradient-corresponding to the flow of a hot medium-is investigated. Presupposing circular symmetry and plane strain conditions, the problem is amenable to an analytical treatment. It is found that-depending on the temperature difference between the outer and ...
Citation Formats
C. E. Fırat, “Effect of roughness on flow measurements in sloping rectangular channels with free overfall,” M.S. - Master of Science, Middle East Technical University, 2004.