Stall Inception in a Boundary Layer Ingesting Fan

Fluid Dynamics Characteristics during Stall Inception Process in a Centrifugal Fan

Based on the three-dimensional elliptic governing equations and the throttle model, an unsteady numerical simulation of rotating stall is undertaken in the case of G4-73 type centrifugal fan and the correctness of simulation results is verified by experiments. In this study a new rotating stall inception criterion is put forward, that the inlet flow or outlet back pressure fluctuations graduall...

Local Nonlinear Control of Stall Inception in Axial Flow Compressors

A combination of theoretical and computational nonlinear analysis techniques are used to study the scenario of bifurcations responsible for the initiation of rotating stall in an axial ow compressor model. It is found that viscosity tends to damp higher-frequency modes and so results in a sequence of bifurcations along the uniform-ow solution branch to stall cells of diierent mode number. Lower...

Active control of compressor stall inception: a bifurcation-theoretic approach

Characterization of Aerodynamic Performance of Boundary-layer-ingesting Inlet under Crosswind

NASA has been studying future transport concepts, envisioned to be technically realizable in the timeframe of 20202030, to meet environmental and performance goals. One concept receiving considerable interest involves a propulsion system embedded into a hybrid wingbody aircraft. While offering significant advantages in fuel savings and noise reduction by this concept, there are several technica...

A hybrid method for singularly perturbed delay boundary value problems exhibiting a right boundary layer

The aim of this paper is to present a numerical method for singularly perturbed convection-diffusion problems with a delay. The method is a combination of the asymptotic expansion technique and the reproducing kernel method (RKM). First an asymptotic expansion for the solution of the given singularly perturbed delayed boundary value problem is constructed. Then the reduced regular delayed diffe...