Fluid–dynamic analysis of a multi–blade gravity damper

Abstract This paper addresses a computational fluid–dynamics study of a multi–blade inlet damper for gas turbine power plants. This device is used in the aspiration duct of the aforementioned plants with the aim to control the air mass flow rate, to dump flow turbulence and to guarantee the plant security. Nowadays the flat plate is the standard shape for damper blades. Clearly the device is rather simple but the operating conditions may prove burdensome. This is related to the vortex shedding developing behind the damper blades. If the shedding frequency of the vortices is close to the resonance frequency of the structure it generates a synchronism that involves the oscillation growth. This can lead to the structure damage. In this research work we have devised a new airfoil shaped blade for inlet dampers in order to suppress the vortex shedding phenomenon behind the damper blades. A proper numerical analysis of the damper blades pitching stability requires to solve a two-way fluid–rigid body interaction problem. Moreover the overset mesh method is strictly needed to investigate the blades motion due to aerodynamic interactions; as a matter of fact other techniques cannot be advocated for this problem since blades closure requirements produce the overlap of moving zones. For this reason we have developed a specific approach, based on the above mentioned techniques, to investigate the dynamic behaviour of the blades of a inlet damper. The obtained results show as the new blades have a very good pitching stability.

[1]  Ning Qin,et al.  Wind tunnel and numerical study of a small vertical axis wind turbine , 2008 .

[2]  Piergiovanni Marzocca,et al.  Divergence and flutter of shear deformable aircraft swept wings subjected to roll angular velocity , 2010 .

[3]  Ernesto Benini,et al.  The Darrieus wind turbine: Proposal for a new performance prediction model based on CFD , 2011 .

[4]  I. Demirdzic,et al.  Numerical method for coupled fluid flow, heat transfer and stress analysis using unstructured moving meshes with cells of arbitrary topology , 1995 .

[5]  T. Shih,et al.  A new k-ϵ eddy viscosity model for high reynolds number turbulent flows , 1995 .

[6]  Keerati Suluksna,et al.  Assessment of intermittency transport equations for modeling transition in boundary layers subjected to freestream turbulence , 2008 .

[7]  Jessica K. Hodgins,et al.  Combining Active and Passive Simulations for Secondary Motion , 2000, IEEE Computer Graphics and Applications.

[8]  Florian R. Menter,et al.  Transition Modelling for General Purpose CFD Codes , 2006 .

[9]  Alfio Quarteroni,et al.  Mathematical models and numerical simulations for the America"s Cup , 2005 .

[10]  S. Patankar.  Numerical Heat Transfer and Fluid Flow , 2018, Lecture Notes in Mechanical Engineering.

[11]  R. Ricci,et al.  Unsteady Aerodynamics of a Savonius wind rotor: a new computational approach for the simulation of energy performance , 2010 .

[12]  Ramji Kamakoti,et al.  Fluid–structure interaction for aeroelastic applications , 2004 .

[13]  Grant E. Hearn,et al.  Predictions of aneurysm formation in distensible tubes: part B - application and comparison of alternative approaches , 2013 .

[14]  Markus H. Gross,et al.  Particle-based fluid simulation for interactive applications , 2003, SCA '03.

[15]  Daniel D. Joseph,et al.  Distributed Lagrange multiplier method for particulate flows with collisions , 2003 .

[16]  R. Ricci,et al.  Enhancement of Savonius wind rotor aerodynamic performance: a computational study of new blade shapes and curtain systems , 2015 .

[17]  Joel H. Ferziger,et al.  Computational methods for fluid dynamics , 1996 .

[18]  François Garde,et al.  Numerical investigation of airflow through a Savonius rotor , 2014 .

[19]  Samir Kumar Das,et al.  Mathematical modeling of sway, roll and yaw motions: order-wise analysis to determine coupled characteristics and numerical simulation for restoring moment’s sensitivity analysis , 2010 .

[20]  F. Menter,et al.  A Correlation-Based Transition Model Using Local Variables—Part I: Model Formulation , 2006 .

[21]  Owen M. Griffin.  A universal Strouhal number for the ‘locking-on’ of vortex shedding to the vibrations of bluff cylinders , 1978 .

[22]  T. Shih,et al.  A New K-epsilon Eddy Viscosity Model for High Reynolds Number Turbulent Flows: Model Development and Validation , 1994 .

[23]  T. Hughes,et al.  Isogeometric Fluid–structure Interaction Analysis with Applications to Arterial Blood Flow , 2006 .