Deterministic current-induced spin-orbit torque (SOT) switching of magnetization in a heavy transition metal/ferromagnetic metal/oxide magnetic heterostructure with the ferromagnetic layer being perpendicularly-magnetized typically requires an externally-applied in-plane field to break the switching symmetry. We show that by inserting an in-plane magnetized ferromagnetic layer CoFeB underneath the conventional W/CoFeB/MgO SOT heterostructure, deterministic SOT switching of the perpendicularly-magnetized top CoFeB layer can be realized without the need of in-plane bias field. Kerr imaging study further unveils that the observed switching is mainly dominated by domain nucleation and domain wall motion, which might limit the potentiality of using this type of multilayer stack design for nanoscale SOT-MRAM application. Comparison of the experimental switching behavior with micromagnetic simulations reveals that the deterministic switching in our devices cannot be explained by the stray field contribution of the in-plane magnetized layer, and the roughness-caused Néel coupling effect might play a more important role in achieving the observed field-free deterministic switching. *

This paper presents time-averaged data for high-Reynolds-number hypersonic shock-wave/boundary-layer interactions, using a body of revolution to achieve high standards of two-dimensionality. The data are collected at nominal Mach 8.9, but a calibration is included that permits weak flow gradients in the test section to be incorporated as part of the data interpretation or flow modelling. The axisymmetric turbulent test boundary layer is developed on a hollow cylinder, aligned axially with the flow. The shock-wave interaction with this boundary layer is then generated by two separate configurations. Firstly, an impinging shock-wave case, that uses a concentric cowl to radiate an axisymmetric shock system onto the test boundary layer: for this case both an attached flow and a separated flow interaction are formed. Secondly, use of a conical-flare afterbody to produce a separated flow interaction. Quantitative data are presented for surface pressures and heat transfer, supported by some schlieren visualization and surface oil flows. A restricted CFD programme is included to assist the interpretation of the experiments.

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This paper introduces the methodology and lessons learned during the design of the LAPCAT MR1 hypersonic passenger vehicle. The MR1 was designed for Mach 8 cruise flight and antipodal ranges for up 300 passengers using a turbine based combined cycle which included Ramjet and Scramjet propulsion at high Mach numbers. Waverider design methods were used to create an aerodynamic system with sufficient lift capabilities over the entire Mach range. The propulsion system is a dorsal type as opposed to most hypersonic vehicle designs. Preliminary design alterations which are being incorporated as part of the second phase design are introduced. Nomenclature a = acceleration β = Angle between earth axis and body axis aoa = angle of attack c = Speed of sound ATR = Air Turbo Rocket CFD = Computational Fluid Dynamics CV = Control Volume Isp = Specific Impulse (s) L/D = Lift/Drag Ma = Mach Number RE = Rocket Ejector RJ = RamJet SJ = SCRamJet t = time θ = Angle between thrust vector and body axis V = Velocity M 0 = Initial Mass M 1 = Final Mass x = Ratio of lift to mass