5269

4939

كارشناسي ارشد

آبياري و زهكشي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده كشاورزي

1388

سيزده،235ص.:مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

حسين افضلي مهر

اسماعيل لندي،سيد حسين سقائيان نژاد

23/3/89

منوچهر حيدرپور،سيدجليل رضوي

1396/10/02

كتابنامه

مهندسي كشاورزي

ID4939

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Investigation of Influence of Wall Vegetation Cover and Non Cohesive Sediment in Bed of a Flume on Turbulent Flow Components under Favorable Pressure Gradient Elham Fazel Najafabadi elham fazel@yahoo com March 03 2010 Department of Water Engineering College of Agriculture Isfahan University of Technology Isfahan 84156 Iran Degree M Sc Language Farsi Hossein Afzalimehr hafzali@cc iut ac ir Abstract Many of free surface flow are at interaction with vegetation For example in natural flows with vegetation cover banks and channel inside indicate spatial pattern flows for velocity and Reynolds stress distribution This matter demonstrate attention of study interaction between water particle sediment and vegetation cover in hydrodynamic and river engineering In defiance of vegetation cover effect in hydrodynamic and ecologic operation of environment in non uniform flow structure there are many unknown subjects for studying The subject of this research is studying of velocity and resistance changes because of banks cover vegetation changes In this research used an Acoustic Doppler Velocimeter ADV for taking data and studied Reynolds stress and turbulence distributions Experiments were carried out in an 8m long 40cm wide and 60cm high re circulating flume At the banks of channel is attached cover vegetation likeness rice stems Experiments is performed in 11 runs consist of one run without bed slope and with cover vegetation in banks one run with 2 bed slope and without cover vegetation in banks and 9 runs with varying slopes and varying discharges The numbers of sections in every run are 3 sections and 3 velocity profiles are selected in every section for cover vegetation runs Velocity profiles at 3 and 6 distance from bank vegetation showed S shape distributions In the presence of cover vegetation logarithmic law validity was higher than those without presence cover vegetation runs and thickness of inner layer was larger The amounts of shear stress in presence of cover vegetation for reason of increase of momentum absorption area are larger than those same amounts for without cover vegetation Discharge change create no change in velocity profile and point velocity amount in center line channel but in 3 and 6 cm distance from bank vegetation increase of discharge lead to decrease of velocity in inner layer Increase of bed slope lead to decrease of shear stress amount in center line channel that of course this decrease isn t considerable Results showed in center line channel at distance between bed channel and y h 0 3 normal stress are dispersed This dispersion was larger for 2 5 and amount of that dispersion was also larger than other slopes Thus from y h 0 3 up to free surface normal stress for various slopes and in center line channel had large difference and those distributions are coincide with each other but by nearing to bank vegetation is showed that with increasing slopes increase normal stress On the other hand normal stress for 3 and 6 cm distance from bank vegetation data dispersion become lower Key words Cover vegetation Non uniform flow Reynolds stress Flow resistance

حسين افضلي مهر

اسماعيل لندي،سيد حسين سقائيان نژاد

منوچهر حيدرپور،سيدجليل رضوي