Experimental and numerical investigation of vortex formation at multiple horizontal intakes

Yıldırım, Tuğçe
Although most of the equations given in the literature for critical submergence are for symmetrical single intakes; in practice approach flow conditions are not mainly symmetrical. In this study, formation of the vortices in asymmetrical approach flow conditions was investigated for a multiple water intake structure composed of a reservoir and several pipe systems. Different scenarios were tested when some of the intake units were in operation whereas some others were not. The geometrical and hydraulic conditions of the system such as the distance between the sidewalls of the intake and the flow discharge were altered and the critical submergence required for the formation of the vortex for each test is determined. The variation of dimensionless critical submergence with related dimensionless parameters is presented and empirical equations were derived for single, double and triple intake structures. The results of the experiments were compared with each other and with those presented in the literature. This investigation has done both experimentally and numerically where software namely FLOW-3D was used in the three dimensional numerical simulations. Numerical and experimental results were compared. It was shown that it is not easy to capture air entrainment and free surface dynamics by numerically


Numerical investigation of flow and scour around a vertical circular cylinder
Baykal, Cüneyt; Fuhrman, D. R.; Jacobsen, N. G.; Fredsoe, J. (The Royal Society, 2015-01-28)
Flow and scour around a vertical cylinder exposed to current are investigated by using a three-dimensional numerical model based on incompressible Reynolds-averaged Navier-Stokes equations. The model incorporates (i) k-omega turbulence closure, (ii) vortex-shedding processes, (iii) sediment transport (both bed and suspended load), as well as (iv) bed morphology. The influence of vortex shedding and suspended load on the scour are specifically investigated. For the selected geometry and flow conditions, it i...
Experimental test of vision-based navigation and system identification of an unmanned underwater survey vehicle (SAGA) for the yaw motion
Kartal, Seda Karadeniz; Leblebicioğlu, Mehmet Kemal; Ege, Emre (SAGE Publications, 2019-05-01)
In this study, a nonlinear mathematical model for an unmanned underwater survey vehicle (SAGA) is obtained. The structure of the mathematical model of the vehicle comes from a Newton-Euler formulation. The yaw motion is realized by a suitable combination of right and left thrusters. The navigation problem is solved by using the inertial navigation system and vision-based measurements together. These are integrated to more accurately obtain navigation data for the vehicle. In addition, the magnetic compass i...
Relaxation to steady state in neutral-beam-injected mirrors
Mirnov, V; Demokan, O (1996-05-01)
The time-dependent Vlasov-Boltzmann equation is analytically studied in mirror machines with perpendicular injection. The atomic and collisional processes are taken into account, with their explicit, rigorous forms. A uniform model is assumed by considering a square-well magnetic field configuration, and the mirrors are represented by related boundary conditions on the ion distribution function. It is shown that, the ion density increases from the initial value, drops by a certain amount, then increases aga...
Improved effective damping equation for equivalent linear analysis of seismic-isolated bridges
Dicleli, Murat (SAGE Publications, 2006-02-01)
In this study, an improved effective damping (ED) equation is proposed to obtain more reasonable estimates of the actual nonlinear response of seismic-isolated bridges (SIB) using equivalent linear (EL) analysis procedure. For this purpose, first the EL analysis results using AASHTO's ED equation is evaluated using harmonic and seismic ground motions. The effect of several parameters such as substructure stiffness, isolator properties, and the intensity and frequency characteristics of the ground motion are...
Differential constrains, recursion operators, and logical integrability
Satir, A (Springer Science and Business Media LLC, 1997-10-01)
Differential constraints compatible with the linearized equations of partial differential equations are examined. Recursion operators are obtained by integrating the differential constraints.
Citation Formats
T. Yıldırım, “Experimental and numerical investigation of vortex formation at multiple horizontal intakes,” Ph.D. - Doctoral Program, Middle East Technical University, 2020.