| Summary: | This paper presents an analytic model for the analysis of co-planar turbine fences that
partially span the width of a channel in which the flow is driven by a sinusoidally
oscillating driving head. The thrust presented by the turbines reduces the flow rate
through the channel leading to a solution for overall power that is dependent upon
turbine resistance and flow blockage as well as on channel characteristics. We introduce
a return parameter, in terms of power per turbine area, to assess optimum turbine fence
deployment for a given channel. We find that the optimal deployment rests on a universal
curve independent of the channel characteristics, and that these characteristics, namely
the integrated channel bed friction and a modified channel Froude number moves the
optimum along this curve. We find that blockage considerations play a large role in
the performance of a tidal farm; its achievable power, optimal return, channel flow rate
reduction and device thrust, and that the scales of blockage must be considered even when
designing relatively unblocked farms. The impact of the channel characteristics on the
optimal arrangement, alongside environmental constraints which may limit permissible
flow blockage, are quantified and discussed.
|
|---|