Showing papers by "K. Murali published in 2011"

Effect of vegetation on run-up and wall pressures due to cnoidal waves

Abstract: A comprehensive experimental investigation was carried out to understand the effect of vegetation in attenuating run-up over a plane slope of 1 : 30 due to the propagation of cnoidal waves. Two different types of vegetation configurations, namely tandem and staggered, are considered. Dynamic pressures exerted along a vertical wall fronted by these two vegetation types were measured, and the typical variation of dimensionless peak pressures for different relative depths of submergence of the pressure ports is reported as a function of dimensionless parameters involving the vegetation and wave characteristics. Further, typical results on the variation of the dimensionless peak run-up versus the surf similarity parameter only for the staggered configuration are also herein reported. Finally, the percentage reduction in wave run-up and pressures on the wall due to the presence of wall fronted by vegetation are reported.

Effect of the Tidal Currents at the Amphidromes on the Characteristics of an N-Wave-Type Tsunami

Abstract: The disturbance due to a tsunami is always coupled with permanent harmonic ocean tides. The tsunami based on its time of occurrence will combine with a particular tidal phase. Thus, a coast will experience a modified water level due to a high- or low-tide situation. On the other hand, the tidal current at the amphidromes may act as an attenuator or amplifier of the tsunami prior to its arrival at the shore. A one-dimensional numerical study has been carried out to demonstrate the effect of the amphidromic current on tsunami characteristics. A realistic N-wave profile of the initial perturbation has been considered for the initiation of a tsunami. The interaction of the amphidromic current with the phase velocity of an N-wave-type tsunami and the subsequent run-up along the shore has been investigated in this paper.

Role of Vegetal Configuration on the Pressures Due to Cnoidal Waves on a Wall

Abstract: The dynamic pressures exerted on a vertical wall due to cnoidal waves have been investigated in presence and absence of model vegetation on its seaside. The pressures were measured at 3 different elevations along the wall. Tests were conducted with waves of constant height of 0.11m, with its period was varying between 5 and 20secs, thus covering a wide range of Ursell parameter varying between 18 and 700. The model vegetation was positioned adjacent to the wall on its seaside. All the vegetal characteristics including their rigidity are carefully modelled. The peak pressures (pmax) were extracted from the measured time series and are presented in a dimensionless form as a function of parameters governing the characteristics of waves and plantation. Two types of configurations of the green belt with the individual stems of vegetation fixed in tandem and staggered arrangement were considered for the tests. The study indicates that the staggered arrangement of plantation is more effective in attenuating the ...