Variable area jet nozzle using shape memory alloy actuators in an antagonistic design

Abstract

A significant reduction in noise and improved fuel consumption can be achieved by varying the area of a commercial jet engine's fan nozzle. A larger diameter at takeoff and approach can reduce jet velocity reducing noise. Adjusting the diameter in cruise, to account for varying Mach number, altitude, etc, can optimize fan loading and reduce fuel consumption. Boeing recently tested a scaled variable area jet nozzle capable of a 20% area change. Shape Memory Alloy actuators were used to position 12 interlocking panels at the nozzle exit. A closed loop control system was used to maintain a range of constant diameters with varying flow conditions and to vary the diameter under constant flow conditions. Acoustic data by side line microphones and flow field measurements at several cross-sections using PIV was collected at each condition. In this paper the variable area nozzle's design is described. The effect of the nozzle's diameter on its acoustic performance is presented for a range of Mach numbers and mass flow rates. Flow field data is shown including the effects of the joints between the interlocking panels.

High‐Speed Antagonistic Shape Memory Actuator for High Ambient Temperatures

“…This SMA actuator concept is, therefore, different from a standard antagonistic SMA system, in which two wires are working directly against each other. [32][33][34][35][36] An example of an injection molding process with a built-in valve is shown in Figure 5, explaining the patented operating principle in a more detailed way. [37] On the left-hand side, a simplified injection mold cavity with a drilled valve seat is shown.…”

高速流场主动流动控制激励器研究进展

“…Hartmann 管是一个开放式的发声器系统, 为了 更好的应用于流动控制, Raman 等人 [79] 和 Kastner 等 人 [80] [93] 、发动机喷管面积改变 [94] 和发 动机减噪 [95] 中的应用研究, 同时在自适应/智能机翼 和可变体飞行器设计中也具有较好的应用前景.…”

Application of Virtual Reality for Learning the Material Properties of Shape Memory Alloys

“…The applications of SMAs grew extensively by the successive finding of the shape memory properties in other alloys, such as Cu-Al-Ni, Fe-Mn-Si, and Cu-Zn-Al [3][4][5]. More recent applications of SMAs include space antennas, military aircrafts, civil engineering, and medical treatment [6][7][8][9].…”