Prof Mike Gaster BScEng PhD(Lond) FRS
Overview
Interest is mainly focused on problems to do with laminar boundary layers and the breakdown of these flows to turbulence. Current activity is firmly committed to understanding the way that roughness modifies the boundary layer flowing over it and hence the amplification of instabilty wave.Research Area
- Modelling and Simulation in Engineering Systems
Research Topics
| Active control of instability waves to inhibit transition to turbulence |
| Bursting of Laminar Separation Bubbles A series of experiments are being carried out in a large water tunnel in the University of Tucson trying, in the first instance, to repeat experiments carried out at Queen Mary in the 1950's in a wind tunnel. The use of advanced PIV will enable far more details of the flow structure to be measured.... |
| Development of a 'Rapid Solver' for estimating N-Factors |
| Drag reduction on wings by maintaining laminar leading edges. Leading edges can be kept in a laminar state over a suitable range of Reynolds numbers by preventing turbulence contamination from the root by 'Gaster's Bleeding Slot' (patented). Wind tunnel experiments are to be carried out with EADS in the large Filton tunnel. It is expected to obtain some 3% reduction in wing drag.... |
There is a growing interest in applying active flow and noise control in various engineering applications. 1. We proved computationally and by using instability theory that a simple flow control mechanism of blowing and suction can reduce significantly open cavity noise. This type of noise is found in various engineering... |
| Modelling a family of cross-flow velocity profiles on swept wings The velocity profiles in the boundary layers that form on a two-dimensional wing can be represented reasonably well by the Falkner-Skan family using just one shape parameter. Unfortunately three-dimensional profile families defined by the Falkner-Skan-Cooke scheme do not provide reliable cross-flow shapes. A new two parmeter... |
| Non-linear wave breakdown into turbulent spots Modulated linear instability waves grow and develop into non-linear waves in a different wave to monochromatic waves. Very rapid oscillations can be observed at localized position. These evolve into embryo spots that spread out to for true turbulent spots. Detailled measurements will be obtained for comparison to DNS. It has... |
| The boundary layer distortions created by various boundary values |
| The effect of discrete steps & gaps on instability waves |
| The influence of distributed roughness on laminar-turbulent transition |
| The influence of real gas effects on boundary layer instability At high Mach number the properties of the gas are greatly influenced by the high temperatures reached and this modifies the amplification rates of instability waves. Linear wave packets generated by a impulsive excitation will be calculated for a Mach number of 6 for comparison with DNS studies.... |
| The use of compliant coatings to inhibit the growth of instability waves It has been known for some time that boundary layers flowing over suitable coatings can inhibit the amplification of instability waves and hence delay the onset of transition. Suitable substrates for use in water flows can readily be found, but air flow presents problems. We will re-examine the problem and find the necessary... |
| Vortex Motion Behind a slender Cones normal to the flow |
Research Student Graduates
| JAGADEESH, Sakaleshpur Chetan | Dynamics of vortex shredding from slender cones | 2010 |
| ZHANG, Zhenyu | Closed-loop flow control for bundary layer instabilities | 2008 |
| CALOUPIS, E | The disturbance field generated by a periodic jet | 2005 |
| LI, Yong | Active control of boundary layer instabilities | 2005 |