Several fluid flow problems related to propulsion and power generation exhibit strong acoustic resonances. Produced due to interactions of the acoustics with other underlying unsteady mechanisms such as unsteady heat release or shear flow instability, these resonances manifest as large and sustained pressure oscillations. Active control of such resonances has been shown to be highly effective, ...

Engine downsizing allows automotive manufactures to achieve improved efficiency and reduce emissions. Turbocharging can increase the power density of the engine, and therefore plays a vital role in downsizing. Due to the nature of the reciprocating engine, a turbocharger turbine operates in a highly unsteady environment. This paper presents a computational investigation looking at the impact of...

research in convective heat transfer using suspensions of nanometer-sized solid particles in base liquids started only over the past decade. recent investigations on nanofluid, as such suspensions are often called, indicate that the suspended nanoparticles remarkably change the transport properties and heat transfer characteristics of the suspension. bending walls can also improve heat transfer...

Simulation models for unsteady open channel flows have been commercially available for more than 2 decades. Most of these models are now available for personal computers and can be used to study the control of irrigation canals. Studies on automatic control methods and algorithms have been performed on at least half a dozen of the available unsteady-flow simulation models. Although, many of the...

The work presents an artificial compressibility method applied to incompressible Navier-Stokes equations for steady as well as for unsteady flows. Two modifications of unsteady numerical solution by an implicit finite volume method are considered. First one uses large artificial compressibility parameter and the iterative solution approximates unsteady evolution of flow. The second approach int...

The unsteady RANS equations are solved for the internal flow through the first one and a half stages of a transonic compressor operating in an off-design condition. To establish a steady performance prediction, the mixing-plane method is used and reasonable comparison to experimental data is obtained for the design configuration. To predict the fully unsteady flow, the sliding-mesh method is us...

April 10-15, 2016 Abstract A whole-annulus unsteady numerical simulation is carried out to investigate the mechanism of the rotating stall in a 1.5-stage low-speed axial-compressor. By comparing the experimental and numerical results, the numerical results are validated. The numerical simulation captures the most features of the rotating stall of the 1.5-stage compressor observed from the exper...

This paper presents a time-accurate procedure for computing unsteady aerodynamic forces on wings with a full-span oscillating control surface by using sheared grids. In this procedure, the flow is computed by solving the unsteady Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with the one-equation Spalart-Allmaras turbulence model. A module to model control surface oscillations...