A digital filtering algorithm for continuous base flow separation is compared to physically based simulations of base flow. It is shown that the digital filter gives comparable results to model simulations in terms of the multiyear base flow index when a filter coefficient is used that replicates the watershed-specific time delay of model simulations. This way, the application of the heuristic ...

Base-level fall in river beds occurs due to varying natural or unnatural causes. Base-level fall causes the change in the behavior of flow at the location of drop in base-level. In such situations, most of scour occur at the foot of the slope, and slope wall retreats in the upstream direction. This phenomenon widens the wall of the river bank, thus leading to its destruction. The amount of bed ...

the term hydrological drought is applied to represent low water levels in streams, reservoirs and lakes as well as a low groundwater level. base flow index (bfi) as one of low flow indices gives the ratio of base flow to total flow and investigates basin’s ability to store and release of water in drought periods. the objectives of this study were to determine bfi and to validate this index in d...

secondary flow investigation could be regarded as an important issue in open channel flow, in spite of its lower quantity compared to the base flow in the water course. it should be given special consideration because of the influence on some hydraulic factors in open channel, specifically in compound channels. in compound channels' due to the difference in the flow velocity of the main ch...

Two distinct redistribution grids - adaptation techniques, spring analogy and elliptic grid generator are applied to two-dimensional steady, inviscid, shocked flows, and the ability of each technique is examined and compared. Euler equations are solved base on Roe's Reimann solver approach to simulate supersonic flow around a sphere, transonic flow about an airfoil and supersonic flow in a symm...

The stability of flow formed by intersection of two perpendicular flatplates is revisited through a study of the sensitivity to the base flow variation. After a brief presentation of the asymptotic regime, sensitivity functions underlying corner mode (concentrated close to the intersection) and Tollmien-Schlichting modes, with different obliqueness angles, are computed. With this consideration,...

We present a novel theory that determines the sensitivity of linear stability to changes in the density or velocity of a base flow. The sensitivity is based on global direct and adjoint eigenmodes of the linearized Boussinesq equation, and is inspired by constantdensity sensitivity analysis. The theory can be applied broadly to incompressible flows with small density variations, but it specific...

Aerodynamic drag is an important factor in vehicles fuel consumption. Pressure drag which is the main component of total drag is a result of boundary layer separation from vehicle surface. Flow control methods are applied to avoid or at least delay separation. Depending upon whether these methods consume energy to control the flow or not, they are called active or passive control methods. In th...