A 95% cold-rolled Al-20%Sn-1%Cu alloy was heat-treated in a range of temperatures and times to investigate the evolution of mechanical properties and microstructure. The most interesting combination of properties can be achieved between 300 and 400°C in a process that is simpler than what is used in industry. The physical phenomena which are active during the heat treatment are precipitation, recovery, recrystallisation and change in phase distribution due to surface tension. The former two predominate at low temperatures, while the latter achieve faster kinetics at higher temperatures, where recrystallisation is coupled to the change in morphology of the contiguous Sn-phase.

No abstract

No abstract

Aerothermal performance of an asymmetrical-profile, leading-edge jet impingement array is studied using numerical and experimental techniques. This array consists of a single row of 9 jets impinging on a leading edge of diameter ratio D/d = 2, and a distinct suction side/pressure side akin to that of an actual turbine blade. Two different jet-to-target heights are tested, while the jet spacing of 4 jet diameters is kept constant. A range of jet-averaged Reynolds numbers between 20k – 80k are tested. The mean flow field of the mid-jet plane is quantified experimentally, through a non-intrusive experimental method of Particle Image Velocimetry (PIV), while area-averaged heat transfer is measured by the constant temperature copper block technique. The target surface is divided into several copper blocks to investigate the area-averaged heat transfer at each jet. The numerical portion of the presented work serves to investigate the fidelity of the Reynolds Averaged Navier-Stokes (RANS) k-ω turbulence model and how well it can predict the flow field within the geometrical domain of the leading edge.

No abstract