The purpose of this study was to explore the water usage profile of future Vietnamese households by carrying out a controlled living experiment with Vietnamese high-income households. By studying showering time, flow ...The purpose of this study was to explore the water usage profile of future Vietnamese households by carrying out a controlled living experiment with Vietnamese high-income households. By studying showering time, flow rate and toilet-use frequency of these households, the study revealed the water usage believed to be representative of future households in light of continued urbanization. This study also determined that the average time of showering was 9.7 minutes per person per day with an average flow rate of 12 L/minute for the existing shower head and 6.6 L/minute for the water-saving shower head. Toilet usage frequency was 5.25 times per person per day, and there was no difference with the results for an average (middle-income) household.展开更多
Water hammer pressure transient produces large dynamic forces which can damage the pipes and other assemblies in the feed line of a reaction control system(RCS).It has led to the failure of pressure transducers monito...Water hammer pressure transient produces large dynamic forces which can damage the pipes and other assemblies in the feed line of a reaction control system(RCS).It has led to the failure of pressure transducers monitoring the manifold pressure in the feed line of RCS.Therefore,water hammer studies have been carried out to understand its effect in feed line.Feedline system has been simplified to develop a mathematical model and experiments have been carried out at extensive levels.The mathematical model was developed considering pipe of uniform c/s and moving liquid-gas interface.The experimental studies have been done using water as working medium instead of actual propellant.The studies showed that rate of pressurization have a very critical role on the water hammer amplitude.Sensitivity studies have been also carried out to study the effect of density,friction and initial liquid column length on water hammer amplitude.展开更多
文摘The purpose of this study was to explore the water usage profile of future Vietnamese households by carrying out a controlled living experiment with Vietnamese high-income households. By studying showering time, flow rate and toilet-use frequency of these households, the study revealed the water usage believed to be representative of future households in light of continued urbanization. This study also determined that the average time of showering was 9.7 minutes per person per day with an average flow rate of 12 L/minute for the existing shower head and 6.6 L/minute for the water-saving shower head. Toilet usage frequency was 5.25 times per person per day, and there was no difference with the results for an average (middle-income) household.
文摘Water hammer pressure transient produces large dynamic forces which can damage the pipes and other assemblies in the feed line of a reaction control system(RCS).It has led to the failure of pressure transducers monitoring the manifold pressure in the feed line of RCS.Therefore,water hammer studies have been carried out to understand its effect in feed line.Feedline system has been simplified to develop a mathematical model and experiments have been carried out at extensive levels.The mathematical model was developed considering pipe of uniform c/s and moving liquid-gas interface.The experimental studies have been done using water as working medium instead of actual propellant.The studies showed that rate of pressurization have a very critical role on the water hammer amplitude.Sensitivity studies have been also carried out to study the effect of density,friction and initial liquid column length on water hammer amplitude.
基金Supported by Human Resources and Social Security Department Students Abroad Science and Technology Activities Preferred Foundation (Human and Social Council Issued 2008-86)Talent Development Fund Project in Jilin Province (Jilin 2007-259)+6 种基金Jilin Province Science and Technology Development Project (20060577 )Technology Project Jilin Provincial Ministry of Education (20094352006113 2007169)The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry ( 2005-546 )Science Foundation of Changchun Teachers University (2009002)Northeast Normal University Natural Science Foundation for Young Scholar (20050406)~~