This paper studies the relationship between unsteady flow features and instantaneous torque and power performance of straight bladed vertical axis wind turbine at variable tip speed ratios. The rotor unsteady flow field simulation was carried out by using computational fluid dynamics method. The flow physics and the principle of changing flow filed acting on torque performance and power perform...

Numerical simulations of the unsteady flow over a low-aspect-ratio, low Reynolds number semi-circular planform wing are performed using Lattice Boltzmann method. The simulations exactly match the flow conditions and the detailed geometry from previous wind-tunnel experiments, including the flow actuators installed internally along the leading edge of the wing. To reproduce the pulsed-blowing ac...

The purpose of this work is to examine the flow of a binary mixture including chemically inert incompressible Newtonian fluids in a duct of semicircular cross-section. Such a flow model has great significance not only of its own theoretical interest, but also for application to various engineering processes. The governing equations have been solved analytically using the finite Fourier sine and...

This paper presents new, efficient methods for computing finite-time Lyapunov exponent (FTLE) fields in unsteady flows. The methods approximate the particle flow map to eliminate redundant particle integrations in neighboring flow map calculations. Two classes of flow map approximations are investigated based on composition of intermediate flow maps; unidirectional approximation constructs a ti...

In this study, the unsteady squeezing nanofluid flow between two plates with thermal radiation has been investigated. The governing equations of model have transformed to a set nonlinear ordinary differential (ODEs) from partial (PDEs) using suitable similarity variable. optimal auxiliary function method (OAFM) and Runge–Kutta order 4 (RK 4) are used for solution modeled problem. variation numb...

Simulation of a process and analysis of its resulting data in both dynamic and steady-state conditions are fundamental steps in understanding the process in order to design and efficient control of system as well as implementing operational cost reduction scheme. In the present paper, steady and unsteady state simulation of Amir Kabir1, 3 butadiene purification units has been done by using Aspe...

Several approaches for modelling the longitudinal aerodynamic coefficients of a fighter aircraft at high angles of attack, including the unsteady effects are presented. A traditional approach where the model of the coefficient arises in the form of the steady and unsteady effects, the unsteady effect being modelled by means of transfer functions. The second approach uses an internal variable de...

Design of muffler system strongly influences engine efficiency and noise level. Hence, comprehension of flow characteristics inside muffler system is very important. In this study, numerical study of three-dimensional steady and unsteady compressible flow inside muffler system attached to 4-cylinder engine was performed to identify the flow characteristics. To obtain the boundary conditions for...

The rating curve is the relationship between the water stage and the associated discharge in a givensection of a channel. In steady flow, this relationship usually has exponential type, whereas inunsteady it flow has a looped shape. Since direct developing of actual looped rating curve by usinghydrometric methods is merely possible, steady-state rating curve is commonly used as a downstreamboun...