Silting in river is a dynamic process, so it needs to regular desilting. At present, underwater siltation monitoring still its early days and based on experience. This paper puts forward the criterion of discrimination, which flood discharge section decreased by 20%. It used method steady uniform flow open rectangular trapezoidal channel for calculation. The results show that reference values d...

Open-channel bifurcations are the most common water diversion structures in irrigation districts. In conveyance, transport efficiency and sedimentation primary concerns. This study accordingly analyzes influence of open-channel on delivery areas. Herein, three-dimensional flow at an bifurcation was studied via numerical simulations using FLOW-3D software including 15 sets working conditions. Th...

An important feature of most rivers and canals is their habitats for a rich of aquatic vegetation which is extremely important from an environmental and ecological point of view. These variations in habitat mean that it is rare to find a cross-section of a natural channel which has the same roughness along its perimeter. In these channels, flow conditions lead to a complex flow situation with i...

The present work is carried out to investigate heat transfer and friction factor characteristics of fluid (air) flow through turbulent channel i.e. parallel plate heat exchanger for different geometry and designs parameters, with a bottom plate applied to uniform constant heat flux thermal boundary condition, and upper plate is provided with a insulated condition. The fluid domain is designed u...

Heat transfer in the thermal entrance region of trapezoidal microchannels is investigated for hydrodynamically fully developed, single-phase, laminar flow with no-slip conditions. Three-dimensional numerical simulations were performed using a finite-volume approach for trapezoidal channels with a wide range of aspect ratios. The sidewall angles of 54.7 and 45 are chosen to correspond to etch-re...

Difficulties associated with free-surface finite element flow simulations are related to a) nonlinear and advective nature of most hydrodynamic flows, b) requirements for compatibility between velocity and pressure interpolation, c) maintaining a valid computational mesh in the presence of moving boundaries, and d) enforcement of the kinematic conditions at the free surface. Focusing on the las...

Abstract In this paper, several analytical models are presented for the optimal design of a trapezoidal composite channel cross-section. The objective function is cost per unit length channel, which includes excavation and lining costs. To define system, variables including depth, width, side slopes, freeboard, roughness coefficients were used. constraints include Manning’s equation, flow veloc...

Trapezoidal words are finite words having at most n+1 distinct factors of length n, for every n≥ 0. They encompass finite Sturmian words. We distinguish trapezoidal words into two disjoint subsets: open and closed trapezoidal words. A trapezoidal word is closed if its longest repeated prefix has exactly two occurrences in the word, the second one being a suffix of the word. Otherwise it is open...