Showing papers by "K. Murali published in 2013"
TL;DR: An artificial compressibility based fractional step method is analysed against a monolithic scheme for solving incompressible flow equations and it is shown that the AC-CBS and PSPG procedures are identical in structure, except for the stabilization parameters.
Abstract: In this note, an artificial compressibility based fractional step method is analysed against a monolithic scheme for solving incompressible flow equations. The artificial compressibility (AC) procedure presented in this paper is stabilized via a characteristic based split (CBS), and thus it is referred to as the AC-CBS method. The monolithic method used for comparison in the present study is the pressure stabilized Petrov–Galerkin (PSPG) method. It is shown that the AC-CBS and PSPG procedures are identical in structure, except for the stabilization parameters. For unsteady problems, a dual time stepping algorithm is employed in the AC-CBS scheme. Unlike classical fractional step methods, this dual time stepping mechanism circumvents the temporal pressure splitting error, and thus provides the anticipated temporal accuracy. The temporal accuracy of the AC-CBS method is demonstrated via a standard benchmark problem. Up to fourth order time accurate schemes are introduced for a thorough analysis of the AC-CBS scheme.
9 citations
TL;DR: In this paper, a detailed laboratory study is taken up to examine the resistance characteristics of a group of model slender flexible cylinders, where individual cylinders of the group were fixed to the bed in a staggered configuration and a new empirical relationship is proposed for estimation of Manning's n for staggered flexible emerging plantations which is valid for depths of flow greater than 0.8 times the undeflected plant height.
Abstract: Vegetation along a coastline could offer significant protection of the adjoining land area against natural hazards such as storm surge and tsunami. In this context, the flexibility of the individual that stems within the green belt is understood to play an important role in the attenuation of momentum of the incoming waves. The physics of which, is yet to be understood completely. Difficulty in modeling the rigidity of the plantations, both numerically and experimentally, is the main cause for this lack of understanding. In the present work, a detailed laboratory study is taken up to examine the resistance characteristics of a group of model slender flexible cylinders. The individual cylinders of the group were fixed to the bed in a staggered configuration. The size, vegetation density and the elastic modulus of the individual stems were chosen such that the tests covered the practical ranges of vegetation in coastal forestry. The Manning's n for different flow conditions as well as for vegetative parameters was obtained from the physical tests in uniform steady current. The results clearly bring out the variation of flow resistance in terms of flow velocity, density of plantation, individual stem diameter and its elastic property. A new empirical relationship is proposed for estimation of Manning's n for staggered flexible emerging plantations which is valid for depths of flow greater than 0.8 times the undeflected plant height.
3 citations