رفتار ارتعاشي دريچه هاي كشويي تخليه كننده هاي تحتاني سدها در شرايط هيدروليكي مختلف

چكيده انگليسي :

Flow Induced Vibration of Sluice Gates Due to Different Hydraulic Conditions Azadeh jafari azadeh jafari@cv iut ac ir January 20 2014 Civil Engineering Department Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors A R Kabiri Samani akabiri@cc iut ac ir and F Behnamfar farhad@cc iut ac ir AbstractVertical sluice gates are one of the most common hydraulic structures that are used in dam engineering Fluid structure interaction is a frequent problem of design engineers and researchers Present study focuseson the interaction between water flow and sluice gate operation namely flow induced vibration of sluicegates Numerical investigation was performed to study the fluid structure interaction using finite elementmethod Three dimensional behavior of the sluice gate with respect to the boundary conditions of gate andflow was considered According to the results of former investigations the gate upstream face should bebeveled with an angle of 45 to give the best operational condition e g to reduce the gate stream wisevibrations For stream wise gate vibrations the small gate s opening with one degree of freedom fxo fyo 0 1 DOF in x direction where y deflection is blocked where fxo and fyo are respectively have been investigatedpreviously In general in the concept of structural dynamics the fluid induced vibrations are characterizedby a hydrodynamic dimensionless parameter namely reduced velocity This parameter relates to the rationof a typical flow frequency V d where V is the flow velocity and d is the gate s thickness to the solid naturalfrequency n According to former researches the flow induced vibrations of sluice gates establish in threedistinct vibration domains characterized by a range of dimensionless reduced velocity number Numerical results indicate that stream wise gate vibration reduces significantly if the upstream edge of thegate is beveled at an angle of 45 compared to rectangular lip gates However the maximum vibration occursfor the same rate of gate s opening to the gate thickness b The cross flow vibrations have also beeninvestigated for the condition of fxo fyo 1 DOF in y direction and x deflection blocked Numericalmodeling was performed for different values of gate opening to the gate thickness ratios and reducedvelocities ranging between from 2 to 3 5 Results compare well with those of former investigations Flow induced vibrations of sluice gates with 2 DOF was also studied considering the reduced velocities Vrx and Vryfor different values of fxo fyo For fxo fyo 2 89 close to the natural frequency fy0 of the vertical d o f dominantvertical vibrations due to ILEV excitation occur in range 2 Vry 4 Numerical results indicates that horizontalamplitudes in 2 d o f become much larger than the amplitudes of the gate with only one horizontal d o f Close to the natural frequency fx0 of the horizontal d o f vibrations due to MIE excitation occur in range3 5 Vrx 7 Vry 10 Horizontal response vibration in 2 d o f is the same response with only one horizontald o f Keywords Flow induced vibration Gate vibration Numerical modeling Sluice gates

جعفري، آزاده

رفتار ارتعاشي دريچه هاي كشويي تخليه كننده هاي تحتاني سدها در شرايط هيدروليكي مختلف

ارتعاش , دريچه , حل عددي