scholarly journals SHAPE MEMORY ALLOY ACTUATORS ARE USED TO CREATE A VARIABLE AREA JET NOZZLE FOR NOISE REDUCTION: A REVIEW

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Shubham Chavan ◽  
Pratap Gujar
Keyword(s):  
Shape Memory Alloy ◽  
Flow Field ◽  
Shape Memory ◽  
Noise Reduction ◽  
New Technology ◽  
Field Measurements ◽  
Aviation Industry ◽  
Loop Control ◽  
Jet Nozzle ◽  
Asymmetrical Design

The real study details the design and implementation of Shape memory alloy actuators to produce a noise-reducing variable area jet nozzle. A subscale design specification of a changeable area jet nozzle was created using SMA actuators in an asymmetrical design. Commercial transportation planes must be quieter, cleaner, and more efficient, according to the international community. The aviation industry is reacting by developing new technology in order to achieve those objectives. Changing the area of a commercial jet engine's fan nozzle can result in substantial noise reduction and reduced fuel economy. At takeoff and approach, a bigger diameter reduces jet velocity, which reduces noise. In cruise, adjusting the diameter to account for variable Mach numbers, altitude, and other factors helps optimise fan loading and minimise fuel consumption and emissions. Boeing has tested a 20 percent area change scaled variable area jet nozzle. At the nozzle exit, Shape Memory Alloy actuators were utilised to place 12 interlocking panels. To maintain a range of consistent diameters with variable flow circumstances and to alter the diameter under constant flow conditions, a closed loop control system was utilised. At each condition, acoustic data was gathered using side line microphones, and flow field measurements were taken using PIV at various crosssections. The design of a variable area nozzle is explained in this work. The diameter of the nozzle and its influence on acoustic performance are discussed. The effects of the joints between the interlocking panels are seen in the flow field data.

Design of a 2 DOF Shape Memory Alloy Actuator Using SMA Springs

2021 ◽  
Author(s):  
Hussein F. M. Ali ◽  
Youngshik Kim
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Biologically Inspired ◽  
Loop Control ◽  
Actuator System ◽  
Sma Actuator ◽  
Sma Spring ◽  
Two Degree Of Freedom

Abstract In this paper, we developed two degree of freedom shape memory alloy (SMA) actuator using SMA springs. This module can be applied easily to various applications: device holder, artificial finger, grippes, fish robot, and many other biologically inspired applications, where small size and small wight of the actuator are very critical. This actuator is composed of two sets of SMA springs: one set is for the rotation around the X axis (roll angle) and the other set is for the rotation around the Y axis (pitch angle). Each set contains two elements: one SMA spring and one antagonistic SMA spring. We used an inertia sensor (IMU) and two potentiometers for angles feedback. The SMA actuator system is modeled mathematically and then tested experimentally in open-loop and closed-loop control. We designed and experimentally tuned a proportional integrator derivative (PID) controller to follow the set points and to track the desired trajectories. The main goal of the presented controller is to control roll and pitch angles simultaneously in order to satisfy set points and trajectories within the work space. The experimental results show that the two degree of freedom SMA actuator system follows the desired setpoints with acceptable rise time and overshoot.

Broadcast Feedback With Hysteresis Loop Control of Stochastically Behaving Cellular Units With Application to Cellular Shape Memory Alloy Actuators

2008 ◽  
Author(s):  
Levi Wood ◽  
Jun Ueda ◽  
H. Harry Asada
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Refractory Period ◽  
Time Lag ◽  
Hysteresis Loops ◽  
Control Law ◽  
Asymptotically Stable ◽  
Loop Control ◽  
Sma Actuators ◽  
Stable Control

This work develops a probability broadcast feedback controller for an ensemble of stochastically behaving cellular units exhibiting hysteresis. Previous work has developed asymptotically stable control laws for ideal on-off cellular units without any hysteresis or time lag. This work extends previous results by developing an asymptotically stable control law for an ensemble of cells that experience an arbitrary refractory period after a change in output, during which time the cell output is fixed. This refractory period describes the behavior of hysteretic cells such as shape memory alloy (SMA) actuators or biological cell migration. Conditions for stability are obtained using a stochastic Lyapunov function. Simulation of SMA actuators demonstrates the application of the new control law to practical hysteresis loops.

Stochastic recruitment control of shape memory alloy cellular actuators based on multi-state Markov chain model

2021 ◽  
pp. 1045389X2110026
Author(s):  
Chen Zhang ◽  
Jianjiang Cui
Keyword(s):  
Markov Chain ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Markov Chain Model ◽  
Open Loop ◽  
Chain Model ◽  
Control Laws ◽  
Loop Control ◽  
Stochastic Recruitment ◽  
The Stability

A new broadcast stochastic recruitment approach to the control of shape memory alloy (SMA) cellular actuators is proposed. The control design is based on a Markov chain model of multi-state cells, which is able to better characterize the inherent hysteresis of SMA in phase transition. The closed-loop and open-loop control laws are derived from random Lyapunov stability analysis and the stability conditions are analyzed. Simulation experiments demonstrate the effectiveness of the proposed method.

Development of an Ultra-Quiet Fan for Computer Cooling Applications

2014 ◽  
Author(s):  
Zhenyu Wang ◽  
Hui Hu
Keyword(s):  
Flow Field ◽  
Noise Reduction ◽  
Sound Pressure ◽  
Field Measurements ◽  
Vortex Structures ◽  
Tip Clearance ◽  
Axial Fan ◽  
Fan Noise ◽  
Piv Measurements ◽  
Cooling Fan

We report the progress made in our recent study to develop an ultra-quiet axial fan for computer cooling applications. By using a commercially-available cooling fan as the baseline, a number of acoustically tailored modifications are implemented in order to reduce the noise level of the cooling fan, which includes optimizing the rotator blades and guide vanes according to axial fan design theory, adding an intake cone in the front of the hub to guide the airflow into the axial fan smoothly, and reducing the tip clearance to lower the noise generation due to tip vortex structures. A comparison study is conducted to measure the sound pressure level (SPL) of the reformed axial fan in an anechoic chamber, in comparison to that of the prototype fan, in order to assess the effects of the modifications on the fan noise reduction. The measurement results of our preliminary study reveal that, at the same flow rate, the SPL of the reformed fan would be up to 5 dB lower than that of the prototype fan. In addition to measuring the sound pressure levels (SPLs) of the fans, a digital particle image velocimetry (PIV) system is also used to conduct detailed flow field measurements to reveal the changes of the flow characteristics and unsteady vortex structures associated with the modifications. Besides conducting “free-run” PIV measurements to determine the ensemble-averaged statistics of the flow quantities such as mean velocity, Reynolds stress, and turbulence kinetic energy (TKE) distributions at the exit of the axial fan, “phase-locked” PIV measurements are also performed to elucidate further details about evolution of the unsteady vortex structures in fan exhaust in relation to the position of the rotating fan blades. The detailed flow field measurements are correlated with the SPL measurements in order to elucidate underlying physics associated with the fan noise reduction.

Segmented shape memory alloy actuators using hysteresis loop control

2006 ◽  
Vol 15 (2) ◽  
pp. 642-652 ◽  
Author(s):  
Brian Selden ◽  
Kyujin Cho ◽  
H Harry Asada
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Hysteresis Loop ◽  
Loop Control

Flight Test of a Shape Memory Alloy Actuated Adaptive Trailing Edge Flap

2016 ◽  
Author(s):  
F. T. Calkins ◽  
J. H. Mabe
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
High Speed ◽  
Flight Test ◽  
Federal Aviation Administration ◽  
Trailing Edge ◽  
Loop Control ◽  
Rotary Actuator ◽  
Trailing Edge Flaps ◽  
Improved Performance

The Boeing Company has a goal of creating aircraft that are capable of continuous optimization for all flight conditions. Recent advances in SMA actuation and a detailed understanding of wing design were combined to design, build, and safely demonstrate small trailing edge flaps driven by SMA actuation. As part of a 2012 full-scale flight test program a lightweight and compact Shape Memory Alloy (SMA) rotary actuator was integrated into the hinge line of a small flap on the trailing edge of a commercial aircraft wing. This Adaptive Trailing Edge program was part of a Boeing and Federal Aviation Administration (FAA) collaboration. Aerodynamic studies of these small trailing edge flaps show that improved performance requires multiple flap configurations that vary with flight regime. Configurations include small angles of deployment for reduced fuel burn and emissions during high speed cruise and larger angles of deployment for increased lift and lower noise during takeoff and approach. SMA actuation is an ideal compact solution to position these small flaps and increase aircraft performance by simply and efficiently altering the wings aerodynamic characteristics for each flight segment. Closed loop control of the flap’s position, using the SMA actuator, was demonstrated at multiple flight conditions during flight tests. Results of the successful flight test on a 737–800 commercial airplane and the significantly improved performance benefits will be presented. This is the first flight test of an SMA rotary actuator system, which was matured from TRL 4 to TRL 7 during the program.

Adaptive underslung beam using shape-memory alloys for frequency-tuning

2016 ◽  
Vol 28 (10) ◽  
pp. 1260-1271 ◽  
Author(s):  
Filipe Amarante dos Santos ◽  
Corneliu Cismaşiu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Natural Frequency ◽  
Frequency Tuning ◽  
Control Process ◽  
Experimental Tests ◽  
Small Scale ◽  
Temperature Modulation ◽  
Loop Control ◽  
Control Approach

The present article addresses the study of an adaptive-passive beam structure with a shape-memory alloy based actuator. In order to mitigate adverse dynamic effects resulting from externally induced vibrations, the structure is able to automatically tune its natural frequency to avoid resonance. The adaptive-passive beam configuration is based on an underslung cable-stayed girder concept. Its frequency tuning is achieved by temperature modulation of the shape-memory alloy elements through a closed-loop control process based on a proportional-integral-derivative algorithm. The effectiveness of the proposed control solution is substantiated by numerical simulations and experimental tests on a small-scale prototype. The validated numerical model enables the simulation of the proposed control approach in a real-scale footbridge, subjected to a prescribed pedestrian loading. The results are very encouraging and show that, by activating the shape-memory alloy elements, the system is able to successfully shift its natural frequency and to mitigate the effects of induced vibrations.

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