Ibnu Razak - Academia.edu (original) (raw)
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This paper investigates the modelling of a quarter scale offshore oscillating water column (OWC) ... more This paper investigates the modelling of a quarter scale offshore oscillating water column (OWC) wave energy converter (WEC) with results from a prototype device used to validate the model. The OWC WEC utilises a specialised bi-directional air turbine known as the Wells turbine. The paper investigates the modelling of this turbine and studies the electrical output from a generator to be coupled to the turbine. Simulations of the proposed system are carried out under multiple sea state conditions and are compared to results from the prototype device located at an experimental test site in Ireland. Nomenclature Ψ = Non-dimensional pressure coefficient p = Pressure head in the buoy chamber ρ a = Air density N = rotational speed in rads/s D = Diameter of Wells turbine Φ = Non-dimensional flow coefficient Q = Axial flowrate A A = Annular Area A C = Chamber Area U t = Tip velocity Π = Non-dimensional power coefficient T ND = Non-dimensional torque η = Efficiency B t = Damping coefficient B r = Damping ratio I a = Armature Current V a = Armature Voltage B m = DC machine friction factor V c = Capacitor Voltage T mech = Mechanical Torque c Proceedings of the 8th European Wave and Tidal Energy Conference, Uppsala, Sweden, 2009 T em = Electromagnetic Torque T f = Frictional Torque T j = Inertial Torque P elec = Electrical Power P eloss = Electrical Power Losses P mloss = Mechanical Power Losses P pneu = Pneumatic Power
This paper investigates the modelling of a quarter scale offshore oscillating water column (OWC) ... more This paper investigates the modelling of a quarter scale offshore oscillating water column (OWC) wave energy converter (WEC) with results from a prototype device used to validate the model. The OWC WEC utilises a specialised bi-directional air turbine known as the Wells turbine. The paper investigates the modelling of this turbine and studies the electrical output from a generator to be coupled to the turbine. Simulations of the proposed system are carried out under multiple sea state conditions and are compared to results from the prototype device located at an experimental test site in Ireland. Nomenclature Ψ = Non-dimensional pressure coefficient p = Pressure head in the buoy chamber ρ a = Air density N = rotational speed in rads/s D = Diameter of Wells turbine Φ = Non-dimensional flow coefficient Q = Axial flowrate A A = Annular Area A C = Chamber Area U t = Tip velocity Π = Non-dimensional power coefficient T ND = Non-dimensional torque η = Efficiency B t = Damping coefficient B r = Damping ratio I a = Armature Current V a = Armature Voltage B m = DC machine friction factor V c = Capacitor Voltage T mech = Mechanical Torque c Proceedings of the 8th European Wave and Tidal Energy Conference, Uppsala, Sweden, 2009 T em = Electromagnetic Torque T f = Frictional Torque T j = Inertial Torque P elec = Electrical Power P eloss = Electrical Power Losses P mloss = Mechanical Power Losses P pneu = Pneumatic Power