Computational fluid dynamics( CFD) is used to investigate a new type of two-chamber natural gas distributor,which has a natural gas inlet and nine nozzle outlets. The uniformity at the outlet of distributor is practic...Computational fluid dynamics( CFD) is used to investigate a new type of two-chamber natural gas distributor,which has a natural gas inlet and nine nozzle outlets. The uniformity at the outlet of distributor is practice proven to have significant degree influence on its comprehensive performance. To improve the uniformity at the nozzles of the gas distributor,CFD modeling with the RNG k-ε turbulence model is undertaken to understand the mass flow rate of nozzles with reference to different length of chambers and the most optimal length is obtained. The internal flow pattern of the natural gas distributor is analyzed. It is found that the local maximum deviation of the nozzle outflow rate increases with the increase of chambers length when the length is more than 64 mm. The results provide useful suggestions for the optimal design of two-chamber natural gas distributor.展开更多
BACKGROUND Single atrium with single ventricle,or a two-chambered heart,is an extremely rare congenital malformation.Few cases with two-chambered heart surviving to adulthood have been reported.CASE SUMMARY We reporte...BACKGROUND Single atrium with single ventricle,or a two-chambered heart,is an extremely rare congenital malformation.Few cases with two-chambered heart surviving to adulthood have been reported.CASE SUMMARY We reported an adult female patient with a two-chambered heart and situs inversus totalis accompanied by multiple pregnancies and abortions.Magnetic resonance imaging detected a two-chambered heart.B-ultrasound-guided uterine aspiration was performed to absorb 8 g and 10 g of organized villus and decidual tissues,respectively,with a small amount of bleeding.Postoperatively,cyanosis and fatigue-induced shortness of breath were gradually relieved.The patient has currently outlived all similar cases reported so far.CONCLUSION Hemodynamic changes in pregnant women with two-chambered heart impaired cardiac function,responsible for hypoperfusion and miscarriage.展开更多
基金Sponsored by the Beijing Key Lab of Heating,Gas Supply,Ventilating and Air Conditioning Engineering(Grant No.NR2013K04)the Higher School Science and Technology Development Fund of Tianjin(Grant No.20130909)
文摘Computational fluid dynamics( CFD) is used to investigate a new type of two-chamber natural gas distributor,which has a natural gas inlet and nine nozzle outlets. The uniformity at the outlet of distributor is practice proven to have significant degree influence on its comprehensive performance. To improve the uniformity at the nozzles of the gas distributor,CFD modeling with the RNG k-ε turbulence model is undertaken to understand the mass flow rate of nozzles with reference to different length of chambers and the most optimal length is obtained. The internal flow pattern of the natural gas distributor is analyzed. It is found that the local maximum deviation of the nozzle outflow rate increases with the increase of chambers length when the length is more than 64 mm. The results provide useful suggestions for the optimal design of two-chamber natural gas distributor.
基金Supported by Chinese Ministry of Education(No.2020-39)Zunyi Science and Technology Project,No.Zunshi Kehe HZ(2020)246.
文摘BACKGROUND Single atrium with single ventricle,or a two-chambered heart,is an extremely rare congenital malformation.Few cases with two-chambered heart surviving to adulthood have been reported.CASE SUMMARY We reported an adult female patient with a two-chambered heart and situs inversus totalis accompanied by multiple pregnancies and abortions.Magnetic resonance imaging detected a two-chambered heart.B-ultrasound-guided uterine aspiration was performed to absorb 8 g and 10 g of organized villus and decidual tissues,respectively,with a small amount of bleeding.Postoperatively,cyanosis and fatigue-induced shortness of breath were gradually relieved.The patient has currently outlived all similar cases reported so far.CONCLUSION Hemodynamic changes in pregnant women with two-chambered heart impaired cardiac function,responsible for hypoperfusion and miscarriage.
