“The mechanics of quiet airfoils”

Airfoil noise is the major source of noise from wind turbines and is holding back our attempts to mitigate climate change. It also affects a myriad of other technologies, from airliners to computer cooling fans. Noise from all these devices must be reduced to improve public health and prevent diseases such as hypertension and depression. By investigating the fundamental physics of airfoil noise experimentally and through advanced computer simulation, this project will provide new technologies that aims to reduce this noise substantially. This project will assist Australian Industry develop new products for export, improve public health and reduce greenhouse emissions.

More information: http://www.mecheng.adelaide.edu.au/~cdoolan

See all Dr Doolan’s papers here.

Abstract:
A computationally efficient, quasi-one-dimensional supersonic combustion ram- jet (scramjet) propulsion model has been produced for use in hypersonic system design studies. The model solves a series of ordinary differential equations us- ing a 4th order Runga-Kutta method, to describe the gas dynamics within the scramjet duct. Additional models for skin friction and wall heat transfer are also included. The equations are derived assuming an open thermodynamic system with equilibrium or simplified chemistry combustion models. The combustion is also assumed to be mixing rather than kinetically limited. This assumption allows simplification of the modelling and is justified when the model is compared against experimental results. Three test cases are used to validate the performance of the scramjet propulsion model: (1) modelling a reflected shock tunnel hydrogen fu- elled scramjet experiment, (2) a continuous flow hydrogen fuelled scramjet ground test and (3) a segment of the HyShot II flight test. The results show that the model simulates scramjet propulsion with a reasonable degree of accuracy.

http://www.mecheng.adelaide.edu.au/~cdoolan

Updated Research, Student Projects and Teaching Interests.

Simulated using OpenFOAM. For more information of numerical simulation of flow and noise/sound (CFD/CAA), contact Dr Con Doolan

http://midtiby.blogspot.com/2008/07/todonotes-version-2008-07-28.html

New Scientist report that Boeing and Airbus are developing the “morphlet”, a morphing wing tip extension. The idea is that extra fuel savings over and above those already gained with a passive winglet can be obtained. In addition, the morphlet will be able to extend the wing span, increasing aspect ratio and hence aerodynamic efficiency, thereby reducing thrust levels further on landing approach.

This means that engine noise is now even further reduced, making airframe noise more significant. This will further increase the importance of airframe noise, making research in this area even more important.

Flight Global reports on this concept of a mono-tilt-rotor, being developed by AeroCopter. It is supposed to work using an outer ring (not shown) to drive the rotors, that also turn on the inner ring. Rotor propulsion is by “magnets”. It’s aimed at being a fast VTOL aircraft. Interesting if they ever get it to fly.

Excerpt: “AeroCopter has designed a 1,320kg (2,900lb) two-seat personal air vehicle with a cruise speed of at least 220kt (405km/h) and a range of 555km (300nm). There is also an unmanned air vehicle version.”