摘要 |
<p>A flow modulating device comprises flow modulating elements 8 of a shape memory alloy, which are acted upon by resilient elements 10. The flow modulating elements 8 and resilient elements 10 are mounted on a common support ring 6. At one temperature, the flow modulating elements 8 overcome the resilient force of the resilient elements 10 to lie against the wall of a duct 4 in which the device is situated. The flow modulating elements 8 thus offer a relatively low resistance to flow in the duct 4. At a second temperature, the force of the resilient elements 10 overcomes that of the flow modulating elements 8 to deflect them inwardly of the duct 4, so increasing the flow resistance of the device.</p> |