Mechanical and shape memory properties of NiTi triply periodic minimal surface structures fabricated by laser powder bed fusion

Porous NiTi lattice structures are widely used in the manufacture of crucial components owing to their excellent shape memory effect, superelasticity, and high damping capacities. However, the specific strength and lightweight characteristics of porous NiTi lattice structures fabricated by conventional technologies are limited by...

Effect of heat treatment on microstructure and functional properties of additively manufactured NiTi shape memory alloys

Additive manufacturing of NiTi shape memory alloys has attracted attention in recent years, due to design flexibility and feasibility to achieve four-dimensional (4D) function response. To obtain customized 4D functional responses in NiTi structures, tailorable phase transformation temperatures and stress windows as well as one-way or two-way...

Passive louver mechanism for small satellites

A miniaturisation trend in the satellite technology is clearly observable. The new generation of small satellites experiences very large thermal fluctuations, due to their high performance payload and low mass. Contemporary thermal control systems, applicable to small satellites, are mostly characterised by having either an insulative or a...

Design and development of active baseband loadpull system

Gedaechtniseffekte in der Turbulenz

NOTE: REPORT IN GERMAN, ONLY THE ABSTRACT IS IN ENGLISH Memory effects in the flow of fluids are known long since. One has to reckon with such effects when studying the flow of non-Newtonian fluids, for instance when they exhibit a visco-elastic behaviour. Certain phenomena in turbulence also seem to point towards a visco-elastic behaviour. If,...

Memory Effect in a Turbulent Boundary-Layer Flow Due to a Relatively Strong Axial Variation of the Mean-Velocity Gradient

Measurements have been made of the distributions of mean velocity, turbulence intensities and turbulence shear-stress in a turbulent boundary-layer downstream of a hemi-spherical cap attached onto the plane rigid wall. The eddy-viscosity, when computed in the classical way according to Boussinesq's concept from the lateral gradient of the mean...