This paper describes an investigation, which uses a torquemeasurement technique, of effects of axial flow on the stability of Taylor-Couette flow. Two radius ratios, 0.846 and 0.956, are used. The preliminary results show that the critical Taylor number for the onset of Taylor vortices increases monotonically with the Reynolds number of the axial flow and asymptotes to a constant value. Althoug...

A mathematical analysis has been carried out for the axial flow of a Bingham plastic fluid, in the Concentric Cylinder Viscometer which consists of a cylindrical sample holder (the cup) and a cylindrical spindle (the bob) coaxial with the cup. The fluid to be tested flows through the annular gap of the cup and the bob system, sheared by the rotation of the inner cylinder, while the outer cy...

New rotor blades are to be fabricated for the 24 foot diameter, 3-stage axial compressor which provides airflow in the 11by 11-Foot Transonic Wind Tunnel Facility at NASA Ames Research Center in Moffett Field, California. This presents an opportunity to increase the peak Mach number capability of the tunnel by redesigning the compressor for increased pressure ratio. Simulations of the existing ...

A computational method for flutter simulation of turbomachinery cascades is presented. The flow through multiple blade passages is calculated using a time-domain approach with coupled aerodynamic and structural models. The unsteady Euler/Navier-Stokes equations are solved in 2D using a second-order implicit scheme with dual time-stepping and a multigrid method. A structural model for the blades...

Computational analyses such as computational fluid dynamics and computational structural dynamics have made major advances towards maturity as engineering tools. Computational aeroelasticity (CAE) is the integration of these disciplines. As CAE matures, it also finds an increasing role in the design and analysis of aerospace vehicles. This paper presents a survey of the current state of CAE wit...

The turbulent potential model is a Reynolds averaged (RANS) turbulence model that is theoretically capable of capturing non-equilibrium turbulent flows at a computational cost and complexity comparable to two-equation models. The ability of the turbulent potential model to accurately predict nonequilibrium turbulent flows is evaluated in this work. The flow in a spanwise driven channel flow and...

in this study, aerodynamic characteristics of a circular cylinder in an axial flow have been investigated numerically and experimentally. the model has been considered as a cylinder with truncated nose and fineness ratio of 3 (length to diameter ratio of 3). the investigation involves a series of wind tunnel measurements, flow visualization, and numerical simulation. we used different mach numb...