Shape adaptive aerofoils for turbomachinery

Airfoil Save Examples of airfoils in nature and within various vehicles. Though not strictly an airfoil, the dolphin flipper obeys the same principles in a different fluid medium. An airfoil American English or aerofoil British English is the cross-sectional shape of a wingblade of a propellerrotoror turbineor sail as seen in cross-section.

Shape adaptive aerofoils for turbomachinery

In this study, an innovative adaptive variable camber compliant wing, with skin that can change thickness and tailing edge morphing mechanism that is designed based on a new kind of artificial muscles, is designed.

Shape adaptive aerofoils for turbomachinery

Consisted of a compliant base plate and seamless and continuous compliant skin with the artificial muscles embedded in, this trailing edge morphing mechanism is extremely light in weight and efficient in reconfiguration of the wing sectional profile.

To demonstrate the feasibility of this design, a simulative experiment of this kind of artificial muscles was designed and carried out. A demonstrative wing section with simulative driving skin mechanism and the compliant skin was manufactured.

A new selector is introduced to facilitate the searching process and improve the robustness of this method. The results show that this method is capable of designing airfoils for this special wing in a quick and effective way.

Introduction Morphing wing technologies have been widely studied recently due to the demands for safe, affordable and environmental compatible aircrafts.

Power consumption, noise emission and overall aircraft environmental impact can be significantly reduced with enhanced flight performance by morphing technologies.

Aerodynamics

In addition, morphing wing technologies were also proved to be useful in increasing the critical flutter velocities [1, 2] and improving wing aeroelastic efficiency [3]. By introducing variable torsion, through rotate ribs around a fixed aluminum rod, to a wing made of carbon fiber skin except for the trailing edge that is stiff in torsional direction, Vos et al.

This wing demonstrates that sufficient control of the rolling motion of aircraft and maximization of the lift-to-drag ratio can be achieved through active wing twist. Superior aerodynamic performance of seamless skin variable camber wing due to morphing leading edge and trailing edge and span wise wing twist has been demonstrated by Joo et al.

However, development in the field of artificial muscle may provide some visionary solutions to this problem [].

However, these designs suffer some performance, scalability and cost problems due to the restrictions of the artificial muscles. Such as the application of electro-thermally driven shape-memory metal, which can provide fast contraction and large strokes, is restricted by the expense and its hysteretic feature that makes it difficult to control.

Polymeric electric field—driven electro-strictive rubbers and relaxor ferroelectrics are attractive because of their large strokes and high efficiencies but would be difficult to deploy as muscle-like fibers because of the high required electric fields.

However, very recently, Carter et al. Experimental results show that this kind of muscles can hold a weight of 0. The tensile actuation of this kind of artificial muscles by thermal control is shown in the following Fig.

Airfoil | Revolvy

Thermal contraction of the artificial muscles Fig. Conceptual design of the adaptive variable camber compliant wing In this study, based on this new kind of artificial muscles, a new concept named Driving Skin, which integrates driving mechanism made of artificial muscles with compliant skin to provide actuation force for morphing mechanism so as to reduce overall weight of the whole wing and enhance aerodynamic force resistance of morphing part, is proposed.

An innovative wing with this driving skin and compliant skin that can change wing thickness is designed. Consisted of a compliant base plate, seamless and continuous compliant driving skin, this trailing edge morphing mechanism hereinafter refers to as driving skin mechanism is extremely light in weight and efficient in reconfiguration of the wing profile.

The conceptual design is shown in Fig. A demonstrative wing section with simulative driving skin mechanism and the compliant skin was fabricated shown in Fig. Not like the span twist around a rod that results in different angle-of-attack of the airfoil profiles along the wing span in other studies, this wing is capable of achieving roll control and gust load alleviation to optimize cruise and maneuver conditions by different thickness distribution and trailing edge morphing.

As this variable camber compliant wing can adapt to current flight conditions by changing thickness and the driving skin mechanism, the airfoil may vary under different flight conditions according to different requirements.

Therefore, aerodynamic performance of numerous airfoils under specific flight conditions needs to be investigated in the preliminary design.The airfoil generator code employs Bezier polynomial curves to produce smooth airfoil shapes.

A meanline program combined with an optimizer was used to perform the global optimization.

Wind Engineering

In the airfoil section design, for fast calculations of the airfoil pressure distributions a discrete vortex method is . "An Adaptive Critic Approach to Reference Model Adaptation". AIAA Langari, R., KrishnaKumar, K., Gundy-Burlet, K., Bryant, D., "Neural-Network Based Modeling and Analysis of LP Control Surface Allocation on Aircraft Flight Dynamic Stability and Control".

Otto Lilienthal and the Flying Machine as a Shape-Adaptable Structural System Sir George Cayley and the Task Separation Principle Being Lightweight: A Crucial Requirement. High fidelity optimization of flapping airfoils and wings: David Williams: Stanford: Energy stable high-order methods for simulating unsteady, viscous, compressible flows on unstructured grids: Joshua Leffell: Stanford: An overset time-spectral method for relative motion: George Anderson: Stanford: Shape optimization in.

May 04,  · GRAPE was originally intended for airfoils but has been heavily modified for turbomachinery blades. RVCQ3D is a quasiD Navier-Stokes code for the analysis of blade-to-blade flows in turbomachinery. It includes the effects of rotation, .

Shape adaptive aerofoils for turbomachinery

A TURBOMACHINERY DESIGN TOOL FOR TEACHING DESIGN CONCEPTS FOR AXIAL-FLOW FANS, COMPRESSORS, AND TURBINES Mark G. Turner University of Cincinnati [email protected] Ali Merchant MIT [email protected] Dario Bruna University of Genoa, Italy [email protected] ABSTRACT A new turbomachinery design system, T-AXI, is described and demonstrated.

Airfoil Shape Optimization with Adaptive Mutation Genetic Algorithm