The demand of further increasing bypass ratio of aeroengine will lead to low pressure turbines with higher diameter. Therefore, it is necessary to design a duct to guide the hot gas flow which is expelled from the ups...The demand of further increasing bypass ratio of aeroengine will lead to low pressure turbines with higher diameter. Therefore, it is necessary to design a duct to guide the hot gas flow which is expelled from the upstream high pressure (HP) turbine stage to the downstream low pressure (LP) turbine stage. Named by its position, this kind of duct is always called intermediate turbine ducts (ITDs). Due to the pursuit of higher thrust ratio of the aeroengine, this kind of ITDs has to beas short as possible which leads to aggressive (high diffusion) S-shaped ITDs' geometry. In this paper, two different schemes of high diffusion separation-free S-shaped ITDs were studied with the aid of three-dimensional CFD programs. Although these two ITDs have the same area ratios (AR), because of the different duct length, they have totally different area as well as area change rates. With the detailed calculation results, comparisons were made to investigate the underneath physical mechanisms. Additionally, a direct estimation of the ITDs' loss is given at the end of this paper and some ITDs' novel design idea is proposed to initiate some further discussions.展开更多
The aim of this study is to investigate the effect of the hemofiltration-body surface area on mortality and morbidity during cardiopulmonary bypass (CBP). A total of 226 patients were divided into two groups as hemofi...The aim of this study is to investigate the effect of the hemofiltration-body surface area on mortality and morbidity during cardiopulmonary bypass (CBP). A total of 226 patients were divided into two groups as hemofiltration (HF) performed or not performed. The patients to whom hemofiltration was performed were also divided into three subgroups after the distribution analysis which was done according to body surface area. All patients were compared according to the relationship of hemofiltration-body surface area during cardiopulmonary bypass in the interms of mortality and morbidity. There was no statistically significant relationship between the subgroups according to the amount of hemofiltration by square meters (p = 0.818). There was statistically significant difference in total perfusion times and total hospital stay (p = 0.025;p = 0.038) between the subgroups which were divided by the amount of hemofiltration in square meters. As a result, no effect was observed on the mortality of the relationship between the amount of hemofiltration applied during CBP and body surface area.展开更多
文摘The demand of further increasing bypass ratio of aeroengine will lead to low pressure turbines with higher diameter. Therefore, it is necessary to design a duct to guide the hot gas flow which is expelled from the upstream high pressure (HP) turbine stage to the downstream low pressure (LP) turbine stage. Named by its position, this kind of duct is always called intermediate turbine ducts (ITDs). Due to the pursuit of higher thrust ratio of the aeroengine, this kind of ITDs has to beas short as possible which leads to aggressive (high diffusion) S-shaped ITDs' geometry. In this paper, two different schemes of high diffusion separation-free S-shaped ITDs were studied with the aid of three-dimensional CFD programs. Although these two ITDs have the same area ratios (AR), because of the different duct length, they have totally different area as well as area change rates. With the detailed calculation results, comparisons were made to investigate the underneath physical mechanisms. Additionally, a direct estimation of the ITDs' loss is given at the end of this paper and some ITDs' novel design idea is proposed to initiate some further discussions.
文摘The aim of this study is to investigate the effect of the hemofiltration-body surface area on mortality and morbidity during cardiopulmonary bypass (CBP). A total of 226 patients were divided into two groups as hemofiltration (HF) performed or not performed. The patients to whom hemofiltration was performed were also divided into three subgroups after the distribution analysis which was done according to body surface area. All patients were compared according to the relationship of hemofiltration-body surface area during cardiopulmonary bypass in the interms of mortality and morbidity. There was no statistically significant relationship between the subgroups according to the amount of hemofiltration by square meters (p = 0.818). There was statistically significant difference in total perfusion times and total hospital stay (p = 0.025;p = 0.038) between the subgroups which were divided by the amount of hemofiltration in square meters. As a result, no effect was observed on the mortality of the relationship between the amount of hemofiltration applied during CBP and body surface area.
