Unsteady surface pressures shed light on the turbulent structures of boundary layer flow, which dictate for a large part the aerodynamic and aeroacoustic performance of aerodynamic bodies submersed in a flow. Remote microphone probes (RMP), e.g., pinhole probes, provide advantages compared to flush-mounted probes because of their reduced sensing area.
However, they feature a distinct transfer function (TF) that needs to be taken into account for accurate pressure measurements. Many empirical calibration techniques for such probes introduce spurious resonance into the calibration, which propagate to the measurements. In this study, a semi-empirical calibration method is proposed with the aim of removing the spurious resonance in a physics-driven manner that is less reliant on the operator. Bayesian inversion is used to fit an analytic model for the TF of the RMP to the empirical calibration data. ... Read more

On a daily basis, the Sun experiences solarweather events, such as coronal mass ejections (CMEs) and solar flares. Varying in size, they are characterised by violent outbursts of matter and energy from the Sun’s surface. In the rare case of a CME of significant size hitting Earth, it could have immense consequences for the electrical power grid, especially at auroral latitudes. CMEs cause large disturbances to the Earth’s geomagnetic field, which result in an increased energy flux. In turn, this would induce large power surges in power lines, electrical wiring, and pipelines. If a system is not protected from such surges, it could short-circuit and be damaged or destroyed. Adverse space weather effects are not only limited to Earth-based electronics but also satellites, which are even more exposed to space weather than Earthbased electronics due to trapped particles. Without an early warning of an incoming CME, the damage of an extreme CME would be catastrophic, causing up to $10 trillion in damage just from damaged infrastructure... ... Read more