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Prediction of Transport Properties of Hydrocarbon Aviation Fuels Using TRAPP Methods
황성록,이형주,박원태 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.3
This study presents a methodology and its results for predicting transport properties using two TRAPP methods, adopting CH4 and C3H8 as the reference fluids, over a wide range of temperature and pressure conditions, including both subcritical and supercritical regions. When hydrocarbon aviation fuels circulate in the regenerative cooling system of a hypersonic flight vehicle, endothermic reactions take place and reaction products are created. Here the viscosity and thermal conductivity of representative fuels and some of their products are predicted in the range of temperatures from 400 to 1000 K and pressures from 0.1 to 5.0 MPa. The results are then compared with data from the NIST database in terms of relative deviation. The TRAPP methods are found to be capable of predicting the viscosity and the thermal conductivity of both light and heavy hydrocarbons and their mixtures over a large range of liquid, gas, and supercritical regions. The relative deviations, however, tend to be considerably larger for higher molecular weight hydrocarbons, because the prediction performance for the liquid state is worse than that for the gaseous and supercritical states. It is also observed that the accuracy of the prediction of viscosity by the methane-based TRAPP (m-TRAPP) method is in general much better than that by the propane-based TRAPP (p-TRAPP) method, with an average relative deviation of within 22%. On the other hand, the p-TRAPP method offers excellent predictions of thermal conductivity in both the gas and the liquid regions, with an average relative deviation of within 14%. It would, therefore, be reasonable to use m-TRAPP for predicting the viscosity and p-TRAPP for the thermal conductivity of recirculating aviation fuels and the hydrocarbons produced by the fuels’ endothermic reactions.
Methane-based TRAPP method를 이용한 탄화수소 항공유의 전달 물성치 예측 연구
황성록,이형주 한국분무공학회 2022 한국액체미립화학회지 Vol.27 No.2
This study presents a prediction methodology of transport properties using the methane-based TRAPP (m-TRAPP) method in a wide range of temperature and pressure conditions including both subcritical and supercritical regions, in order to obtain thermo-physical properties for hydrocarbon aviation fuels and their products resulting from endothermic reactions. The viscosity and thermal conductivity are predicted in the temperature range from 300 to 1000 K and the pressure from 0.1 to 5.0 MPa, which includes all of the liquid, gas, and the supercitical regions of representative hydrocarbon fuels. The predicted values are compared with those data obtained from the NIST database. It was demonstrated that the m-TRAPP method can give reasonable predictions of both viscosity and thermal conductivity in the wide range of temperature and pressure conditions studied in this paper. However, there still exists large discrepancy between the current data and established values by NIST, especially for the liquid phase. Compared to the thermal conductivity predictions, the calculated viscosities are in better agreement with the NIST database. In order to consider a wide range of conditions, it is suggested to select an appropriate method through further comparison with another improved prediction methodologies of transport properties.
초임계 탄화수소 항공유의 열역학적 물성치 예측 기법 연구
황성록,이형주,Hwang, Sung-rok,Lee, Hyung Ju 한국분무공학회 2021 한국액체미립화학회지 Vol.26 No.4
This study presents a prediction methodology of thermodynamic properties by using RK-PR Equation of State in a wide range of temperature and pressure conditions including both sub-critical and super-critical regions, in order to obtain thermophysical properties for hydrocarbon aviation fuels and their products resulting from endothermic reactions. The density and the constant pressure specific heat are predicted in the temperature range from 300 to 1000 K and the pressure from 0.1 to 5.0 MPa, which includes all of the liquid and gas phases and the super-critical region of three representative hydrocarbon fuels, and then compared with those data obtained from the NIST database. Results show that the averaged relative deviations of both predicted density and constant pressure specific heat are below 5% in the specified temperature and pressure conditions, and the major sources of the errors are observed near the saturation line and the critical point of each fuel.
황성록,이형주 한국분무공학회 2023 한국액체미립화학회지 Vol.28 No.2
This study presents a numerical simulation investigating hydrodynamic characteristics of high-temperature hydrocarbon aviation fuel injected through a plain orifice injector. The analysis encompassed the temperature range up to the critical point, and the obtained results were compared with prior experimental observations. The analysis unveiled that the injector’s exit pressure remains equivalent to the ambient pressure when the fuel injection temperature is below the boiling point. However, when the fuel temperature surpasses the boiling point, the exit pressure of the injector transitions to the saturated vapor pressure corresponding to the fuel injection temperature. Consequently, the exit pressure of the injector increases in tandem with the rapid increase of the saturation vapor pressure due to escalating fuel temperatures. This rise in the exit pressure necessitates a proportional increase in fuel injection pressure to ensure a fixed fuel mass flow rate. Furthermore, the investigation revealed that the discharge coefficient obtained by applying the exit pressure instead of the ambient pressure did exhibit no decrease, but rather was maintained at a nearly constant value, comparable to its level below the boiling point.
황성록,김진상,윤태호 대한건축학회지회연합회 2008 대한건축학회연합논문집 Vol.10 No.4
The purpose of this study is to confirm and compare the inelastic behavior of the existing school buildings considering infilled masonry walls. Pushover analysis method is used to evaluate the elastic and inelastic response of standard school building. Infilled masonry walls are usually considered as non-structural elements in structural analysis and design, but the behavior of school building considering infilled masonry walls is quite different and the influence of the masonry wall should be included. The results show that the seismic capacity of pure frame building is 0.76 times design base shear of KBC2005 but considering infilled masonry wall the same building has the overstrength factor of 2.82~5.10 according to infilled wall shear strength in short direction and of 1.62 regardless of infilled wall shear strength in long direction.
소음인(少陰人) 가미거풍산(加味祛風散)의 효능(效能)에 관(關)한 실험적(實驗的) 연구(硏究)
황성록,Hwang, Seong-Rock 사상체질의학회 1990 사상체질의학회지 Vol.2 No.1
In order to investigate experimentally the clinical effects of Soumin Kamikop'ungsan (少陰人 加味祛風散) that was prescribed to cure the Wisuhanrihanbyung (胃受寒裡寒病) of Sumin (少陰人) the author experimented various activities of mixed extract from the Sournin Kamikop'ungsan by the method prescribed in the experimental part. The results of the studies were summerized as follows: 1. Analgesic effects by acetic acid and Randall-Sellito experimental method were noted. 2. Anticonvulsive effect to strychnine was noted. 3. The sedation effects by the unbalanced effects of spontaneous momentum by wheel cage method, muscle relaxing action by Rotor rod method were noted. 4. A prolongation of anesthetic time by Thiopental-Na on the mice was noed. 5. The expansion of blood vessels by relaxation of smooth muscle was noted. According to the above results, results of Soumin Kamikop'ungsan on oriental medical references were consistent with the actual experimental results.