Numerical Simulation of Flow Pattern Around T-Shape Groyne Series

Groyne is a rigid hydraulic structure built by an ocean shore (in coastal engineering) or by a bank (in rivers) that interrupts water flow and limits the movement of sediment. In this research, the numerical investigation of the flow pattern around triplex series of T-groyne in a straight line has been studied. Fluent software and k-ε turbulence model have been used to simulate the flow patterns.
Mean flow velocity, groyne length and the distance between groynes, as effective parameters, have been intended to simulate the flow pattern. The results show that by increasing of mean flow velocity near the bed, the flow pattern does not change in the upstream of the first groyne. In the area between the first
and second groynes, rotational flow has been destroyed. The rotational flow has been formed in the area between the second and third groynes and in the area after the third groyne and acceleration has no effect on the flow pattern. In addition, at the level near the surface, the similar flow pattern is observed. By increasing the length of groyne and at the level near the bed, the flow deflection from the edge of the first groyne’s wing gets more and rotational flow is destroyed behind the first groyne. In the area between the first and second groynes, the rotational flow is formed that with an increase in the length of groyne, the vortex core is transmitted to the first groyne and to the wall. In the area after the third groyne, an oval shaped rotational flow becomes larger. In the area between the first and second groynes, the flow pattern has not changed and in the area between the second and third groynes, the dimensions of the rotational flow become smaller. With an increase in the distance between groynes and at the level near the bed, the rate of the flow deflection from the edge of the first groyne’s wing is not changed. In the area between the second and third, the dimensions of the rotational flow get larger and it is transferred from the wall to the wing of the third groyne. In the area after the third groyne, the elliptical rotational flow is shaped. According to the obtained results, the increasing of the length of the groyne has greater impact on the change in the flow structure as compared to the increase the distance between the groynes.