An experimental and analytical study on the feasibility of SMA spring driven actuation of an iris mechanism

Abstract

h i g h l i g h t sAn iris mechanism proposed in response to fluctuations in solar energy. Iris motion controlled with the use of Nickel-Titanium Shape Memory Alloy springs. Variation of the force exerted by SMA spring w.r.t. temperature tested experimentally. An analytical expression that relates the aperture area and crank rotation is given. SMA springs showed promising actuation mechanism as a replacement to motor.

Numerical and experimental investigation of heat transfer in a solar receiver with a variable aperture

“…Thus, compensating for any irradiance fluctuation without the need to disturb the flow pattern. Various aperture mechanisms have been developed with different designs and approaches to make this mechanism much more effective and sustainable for solar reactors [13][14][15].…”

Development of sprinkler with adjustable orifice using iris-type mechanism for variable rate irrigation

“…Another potential approach for obtaining variable discharge emitters consists of using an iris or diaphragm mechanism to adjust the flow cross-section of an orifice. Iris-type mechanisms are usually formed by a combination of overlapped metal blades that form an adjustable orifice enabling control of aperture sizes and have been used in several applications such as imaging systems (Ren et al, 2012), optics (Syms et al, 2004), radiotherapy (Graves et al, 2007), energy beam collimators (Hill, 1984), lens technology (Chang et al, 2000), robotic radiosurgery (Echner et al, 2009), and solar reactors (Rajan et al, 2016).…”