Aero-Structural Design Optimization of Adaptive Shock Control Bumps

Shock control bumps (SCB) are a transonic flow control device that aim to reduce the overall drag due to a normal shock on a typical passenger jet at cruise. The concept of adaptive SCB which can be deployed for best use are investigated through an aero-structural design tool that produces optimal geometries. The optimizer uses a surface based performance metric to highlight the importance of the flow quality around the SCB as well as including a structural element that is required to provide the necessary flexibility to deform. The performance metric produces the target pressure distribution and successfully smears the shock. It is found that the structural constraint does not inhibit bump height and global airfoil performance is not significantly a↵ected, L/D varies < 0.6%. The aerodynamic pressure loading can be utilised to produce a new family of SCB geometries that are unachievable with mechanical actuation alone. The study shows that adaptive SCB that exploit the naturally occurring pressure field around an airfoil in a passive way are a feasible technology to mitigate the poor o↵-design performance of static SCB

Investigation of the discrete effects of suction in large scale arrays for Laminar flow control

An experimental investigation of the destabilising effects of discrete suction perforations for laminar flow control applications was performed. This research was aimed at investigation of the flow physics of large arrays of discrete perforated suction arrays in globally two-dimensional flows. This research also investigated the effect of varying perforation size, free-stream velocity and suction volume flow rate on the amplification and attenuation of excited travelling waves in a two-dimensional laminar flow. It was found that instead of creating local instabilities that destabilise all frequencies, strong suction had the effect of introducing low frequency disturbances while attenuating naturally produced and excited travelling waves for all test cases considered. If the suction was sufficiently strong these low frequency disturbances would appear to dominate over the stabilising effect of suction (on the natural and excited modes). Possible explanations for these disturbances include viscous or acoustic disturbances located within the suction system. Future experiments will attempt to isolate the effect of the plenums to determine if this is the source of these low frequency disturbances

Overview on drag reduction technologies for civil transport aircraft

Communication to : ECCOMAS, Jyvaskyla (Finlande), 24-28 Juillet 2004SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.2004 n.153 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Transport aircraft aerodynamic improvement by numerical optimization

Paru dans 17th ICAS Congress, Stockolm (Sweden), September 9-14, 1990SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1990 n.113 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

The design and testing of an airfoil with hybrid laminar flow control

Communication a : 1st European forum on laminar flow technology, Hambourg (Germany), March 16-18, 1992SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1992 n.22 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

ONERA activities on high-lift devices for transport aircraft

Communication to : CEAS European Forum High-lift and Separation control, University of Bath (UK), March 29-31, 1995Available at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1995 n.48 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc

ONERA activities on drag reduction

Paru dans 17th ICAS Congress, Stockolm (Sweden), September 9-14, 1990SIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : 22419, issue : a.1990 n.114 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc