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Effect of Surface Roughness and Reynolds Number on Compressor Cascade Performance
Seung Chul Back(백승철),Seung Jin Song(송성진) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11
An experimental work has been conducted in a linear compressor cascade to find out the effect of surface roughness and Reynolds number. Surveys were conducted with different roughness size and Reynolds number. The k<SUB>s</SUB>/c value of each roughness is 0.0006, 0.0090, 0.00150, 0.00213, and 0.00425. The range of Reynolds number is 300,000~600,000 and conducted with roughened blade, which roughness Ra is 2.89 microns. Flow pressure, velocity, and angle have been found out via 5 hole probe. Pressure loss and deviation increased with increasing roughness. In the low Reynolds number under 500,000, tested roughness does not affect to the performance of compressor cascade. However, roughness is very sensitive to pressure loss in high Reynolds number over 550,000.
Seung Ho Cho(조승호),Taehyoun Kim(김태현),Seung Jin Song(송성진) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5
A few fluid structure interaction analyses have been developed for turbomachinery blades in comparison with aircraft wings. Also, the existing aeroelastic analyses for turbomachinery blades have been mostly limited to cases with a steady freestream. In reality, however, the inflowing freestream is often pulsating. Therefore, this paper presents stability and forced response analyses of an isolated three-dimensional blade under pulsating freestream conditions. A new three-dimensional unsteady vortex lattice model under a pulsating freestream has been developed in discrete time domain to examine unsteady aerodynamic forces acting on a vibrating blade. The blade’s structural behaviors have been analyzed by using a three-dimensional plate model. In the aeroelastic analysis, the flutter onset of a blade under pulsating freestream is predicted by the Floquet analysis. The new time domain method can predict aeroelastic stability as well as time history.
백승철(Seung-Chul Baek),손정락(Jeong L. Sohn),송성진(Seung Jin Song) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11
Coal is one of the most abundant and cheapest energy sources in the earth, but its typical combustion product, CO₂, is related with serious recent environmental issues such as global warming. The Integrated Coal Gasification Combined Cycle (IGCC) with CO₂ sequestration is one of the most promising options to produce electricity using a relatively cheap fuel (coal) with minimum impact on environment. In IGCC power generation systems, some chemical reactions are required to gasify coal to produce syngases such as H₂ and CO, which would be burnt in the combustor to produce heat for power generation, with a penalty of additional energy consumption. In this paper, several chemical reactions for the gasification of coal are considered and their characteristics are investigated.
슈라우드 축류압축기에서 누수접선방향속도가 블레이드 구간 유동에 미치는 영향
김진욱(Jin Wook Kim),손대웅(Dae Woong Sohn),김동범(Tongbeum Kim),송성진(Seung Jin Song) 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-
Although compressor blades have long been shrouded for aerodynamic and structural reasons, the impact of the leakage flow in the shroud cavities on passage flows has only recently been investigated. Furthermore, the tangential velocity of the leakage flow, set by the blading and the relative motion between rotating and stationary surfaces, has a strong influence on the passage flow. Yet the influence of the tangential velocity variation on the main flow in the blade passage are unknown. Therefore, this paper reports on an experimental investigation of the axial evolution of loss generation in the blade passage in shrouded axial compressor cascades subject to the variation of leakage tangential velocity. The newly found results are as follows. First, increasing tangential velocity of the leakage flow reduces loss at 10% and 50% chordwise locations in the passage. However, most of the blockage and loss reductions occurs in the aft half chord and downstream of the blade passage. Second, the increasing tangential velocity spreads the loss core, which is originally concentrated in the suction side hub corner, in the pitchwise direction. Thus, the loss core becomes more two-dimensional, and the region's radial extent is reduced. Third, increasing tangential velocity of the leakage flow makes the near hub passage flow more radially uniform. Consequently, the shear and resultant mixing loss between the passage and leakage flows are reduced near the hub, reducing the overall loss.
박응식,송성진,홍용식,Park, Eung-Sik,Song, Seung-Jin,Hong, Yong-Shik 한국유체기계학회 1998 한국유체기계학회 논문집 Vol.1 No.1
To investigate turbine flow fields under realistic conditions, a rotating turbine test facility has been developed at the Inha University Propulsion Laboratory. The experimental facility consists of an air inlet, settling chamber, single turbine stage test section, and diffuser. This turbine has a design flow coefficient of 0.55 and work coefficient of 1.88. The turbine test rig has four features. First, a large scale test section improves space resolution. Second, low speed rpm enhances safety and reduces required power, Third, DC motor/generator is able to regenerate blower power. Fourth, various types of experiment can be carried out.
윤용상,송성진,김홍원,조성희,Yoon, Yong-Sang,Song, Seung-Jin,Kim, Hong-Won,Cho, Sung-Hee 한국유체기계학회 2001 한국유체기계학회 논문집 Vol.4 No.3
This paper describes a turbine test program conducted at Seoul National University(SNU). To measure blades' aerodynamic performance, either linear(2-Dimensional) or annular(3-Dimensional) cascades are often used. However, neither cascade can consider effects such as those due to rotation or rotor-stator interaction. Therefore, a rotating test facility for axial turbines has been designed and built at SNU, and its description is given in this paper. The results from an axial turbine performance test are presented. At the design point, the measured efficiency agrees with the efficiency predicted by a meanline analysis. At off design points, however, the measured and predicted efficiencies diverge. The most likely cause is hypothesized to be the inaccuracy of correlations used in the meanline analysis at off design points.