Seung Jin Song

Peer Reviewed

An experimental investigation has been conducted on rotating cavitation in a turbopump inducer. Previous research suggested that incidence angle variation leads to rotating cavitation. This study, using particle image velocimetry (PIV) method, provides the first measurement of the incidence angle distribution near the tip region of an inducer blade's leading edge with and without rotating cavitation. Without rotating cavitation, the incidence angle near the leading edge of the following blade is

This paper presents an analytical study of flow redistribution in a compressor stage due to asymmetric tip clearance distribution. The entire stage is modeled as an actuator disk and it is assumed that upstream and downstream flow fields are determined by the local tip clearance. The flow is assumed to be inviscid and incompressible. First, an axisymmetric flow model is used to connect upstream and downstream flows. Second, a linear perturbation approximation is used for nonaxisymmetric analysis

A mechanical model which can predict mode I delamination failure of laminated composites has been developed. A beam on a nonlinear spring foundation was used to model experimental results obtained from DCB type fracture specimens. The entire thickness of the beam specimen was used as a spring length, and a nonuniform strain distribution throughout the spring length was utilized, based on the 2-D asymptotic solution of the stress field near a crack tip. The failure condition of the spring foundat

An experimental study has been conducted to investigate the effects of transitionally rough surface on the flat-plate boundary layer transition. Transitional boundary layers with three different flat plates (ks+ = 0.07 ∼ 0.19, 2.71 ∼ 7.05, and 13.65 ∼ 41.09) have been measured with a single-sensor hot-wire probe. All of the measurements have been conducted under zero pressure gradient (ZPG) at the fixed Reynolds number (ReL) and freestream turbulence intensity (Tu) of 3.05 × 106 and 0.2%. Transi

Abstract This paper investigates the influence of additive manufacturing (AM) surface roughness on the aerodynamic performance of axial compressor blades. Though the AM offers advantages such as complex geometry fabrication and reduced material waste, its inherent surface roughness presents challenges in meeting compressor performance requirements. Previous studies have explored the implications of surface roughness on compressor performance. However, the existing literature on surface roughness

This paper presents an analytical study of flow redistribution in a compressor stage due to asymmetric tip clearance distribution. The entire stage is modeled as an actuator disc, and it is assumed that upstream and downstream flow fields are determined by the local tip clearance. The flow is assumed to be inviscid and incompressible. First, an axisymmetric flow model is used to connect upstream and downstream flows. Second, a linear perturbation approximation is used for non-axisymmetric analys

Rotordynamic effects caused by nonaxisymmetric rotor-tip clearance in an axial compressor stage have been analyzed. Two coupled actuator discanalyses are carried out at blade (meridional plane )andradius(radial plane ) scales. Continuity, axial, and tangential momentum equations are used to connect upstream and downstream e ows across the compressor stage, and a small perturbation analysis is used to obtain e owe eld nonuniformities. Predictions indicate the following. Relative to the passage e