• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.131-135
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• 2010

In the present study, the effects of the stagger angles on the aerodynamic performances in the vaned centrifugal compressor has been investigated by CFD methods. The diffuser vane angles were vane angles were varied in the range of ${\pm}10$ deg. from the intial-design points. The commercial Navier-Stokes solver, ANSYS-CFX were applied to solve the impeller-diffuser flowfields. Through the numerical results, the desirable setting angles were proposed to fit the best performance to the variation of the operating conditions.

• Journal of computational fluids engineering
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• v.15 no.3
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• pp.60-65
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• 2010

In the present study, the effects of the stagger angles on the aerodynamic performances in the vaned centrifugal compressor has been investigated by CFD methods. The diffuser vane angles were varied in the range of ${\pm}10$ deg. from the initial-design points. The commercial Navier-Stokes solver, ANSYS-CFX were applied to solve the impeller-diffuser flowfields. Through the numerical results, the desirable setting angles were proposed to fit the best performance to the variation of the operating conditions.

• Journal of computational fluids engineering
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• v.16 no.3
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• pp.75-81
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• 2011

The turbo blowers having large power capacity are generally composed of the variable inlet guide vane, the impeller and the variable diffuser. In the present study, the effect of the stagger angles on the aerodynamic performances has been investigated by CFD methods. The design specifications of the reference model having 400kW power were given as 7.43kg/s of mass flow rate, 1.66 of pressure ratio with 12000rpm of impeller rotating speed. As the first simulation parameter, the diffuser vane angle was varied in the range of ${\pm}$20 degree from the initial-design point. The inlet guide vane angles, as the second one, was changed in the range of ${\pm}$40 degree from the initial-design point. The commercial Navier-Stokes solver, ANSYS-CFX, was applied to solve the three-dimensional unsteady flow fields inside the turbo blower. Through the numerical results, the desirable setting angles were proposed to fit the best performance to the variation of the operating conditions.

• Journal of Animal Environmental Science
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• v.10 no.1
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• pp.37-46
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• 2004

In order to investigate the effect of floor condition on the fattening performance of cattle, sixteen finishing Hanwoo steers of weighting 570kg were fed for 16 weeks to slaughter on two types of sawdust bedding pen oriented to the south(SP) and the north(NP) then obtained following results. The floor condition of SP roofed by transparent material was dry and flat during overall experimental period, whereas, that of NP roofed by solid slate was muddy and rough even in summer and fall, and then frozen in winter period resulted in interfering with the locomotion and resting behavior of steers. Average daily dry matter intake of steers was not different between tow treatments, however, the average daily gain of steers in NP and SP was 0.64kg and 0.75kg, respectively, meaning that gained 14.3% less for the NP group(p<0.05), accordingly, feed requirement(feed/gain) and TDN/gain increased by 15.9% and 15.5%, respectively. No significant differences were found in slaughter weight, carcass weight, dressing percentage, meat yield index and meat quality traits between two treatments. In conclusion, this study revealed that poor floor condition of feeding pen could decrease weight gain and feed efficiency of cattle by increasing energy consumption for locomotion and conductive energy loss while resting on the floor surface. These results indicates that housing orientation of cattle shed and the selection of roof material are important factors in beef cattle production.