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Simulation of laminar flow passing through a T-splitter plate and bridge pier.

Qasim Rafi Mohammed, Jabbar Tahseen Ali, Faisal Safaa Hameed

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2023

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Vol. 32, No. 2

135--154

EN

The present analysis focuses on the investigation of the two-dimensional flow passing a bridge pier nearby a splitter plate in different regimes of a laminar flow. The splitter plate is T-shaped and two different cases have been studied based on the form of the splitter plate relative to the bridge pier. The analysis is implemented for steady and incompressible water flow in an open channel. The current study deals with velocity vectors, drag coefficients, lift coefficients, and skin friction. The analysis of the velocity vector gave a good indicator about the separation process and dissipation, which occurs at the splitter plate before the occurrence of these processes at the front face of the pier, especially the flow separation process. Moreover, the velocity vector gave a good image about the flow direction at two regions, the first region is located between the rear portion of the splitter plate and the frontal face of the pier, while the second region is the wake region, which is located at the downstream of the pier. Negative drag coefficient, lift coefficient, and skin friction coefficient values are obtained from the analysis. This happens due to the existence of the splitter plate that leads to the reduction of these values.

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Bayesian Regression Based Approach for Beam Deflection Estimation

Batbooti Raed S., Mohammed Bassam A., Jabbar Tahseen Ali, Faisal Safaa Hameed

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 3

206--213

EN

Deflection of a beam is the movement of the beam from its initial position to another position depending on the applied load. Beam deflection estimation gives an indication about the possible deformation of the beam. A parametric Bayesian linear based model is introduced to mimic the experimentally collected data to estimate the stochastic deflection of a simply supported beam. A Gaussian noise is assumed to understand the stochastic behavior of the beam deflection as well as a Gaussian prior. The model mapping function used in this work is known as radial basis function, which can be linear or nonlinear. Three basis functions are compared, namely are linear, Gaussian and modified Gaussian function proposed in this work. The modified Gaussian function is a simple function introduced in this work. The performance of the functions is analyzed for three central concentrated loads. The best model can describe the observed data is found to be the modified Gaussian model with regularization factor of 0.9 for three loading cases. The prediction based linear basis function is better than the use of the Gaussian basis function prediction according to error of estimation. The maximum RMS error obtained for modified Gaussian radial basis function corresponding to central load of 4kg is smaller than that of a theoretical based model for the same loading conditions.

3

Impact of T-Splitter on the Laminar Flow Field around Cylinder Pier

Qasim Rafi Mohammed, Faisal Safaa Hameed, Jabbar Tahseen Ali

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 5

202--215

EN

The hydrodynamic pattern, which surrounds the pier near a splitter that has T-shape, is investigated by adopting a numerical method and using ANSYS Fluent Software to achieve computation. The essential objective of this paper refers to revealing the behavior of the hydrodynamic field around the pier due to the existence of the upstream splitter plate. The T-splitter plate has not been used in previous works for controlling the flow field around the cylinder body. The main assumptions adopted in solving the hydrodynamic problem are incompressible, steady, and laminar flow. Reynolds number values are taken from 40 to 200 to guarantee laminar flow with laminar vortex street. The numerical investigation focuses on two main variables. These variables are the horizontal distance between the rear portion of a splitter and the pier center and bubble length. The numerical study comprises pressure contours, water velocity contours, and streamlines. Results reveal that bubbles are generated and developed due to the existence of the splitter. Four bubbles are generated, two of them are formed in the region between the splitter rear portion and pier leading portion and the other two bubbles are formed at the cylindrical pier wake region. The size and length of these four bubbles are dominated by the Reynolds number, these bubbles are non-symmetrical. It is revealed from the solution that with the rise in Reynolds number values then the disturbance will be increased simultaneously. The horizontal distance dominates the hydraulic response, which is described by the streamlines, pressure contours, and water flow contours. Furthermore, the Reynolds number has a significant influence on the pressure contours, water flow contours, and streamlines. Finally, a correlation equation is derived relying on bubble length, horizontal distance, and Reynolds number.