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Interactions between shock waves and boundary layers produce flow separations and augmented pressure/thermal loads in hypersonic flight. This study provides details of Mach 7 impinging-shock-flat-plate experiments conducted in the T4 Stalker Tube. Measurements were taken at flow conditions of Mach 7.0 (2.44 MJ kg
$^{-1}$) and Mach 7.7 (2.88 MJ kg
$^{-1}$) flight enthalpies with a range of freestream unit Reynolds numbers from 
$1.43 \times 10^{6}$ m
$^{-1}$ to 
$5.01 \times 10^{6}$ m
$^{-1}$. A shock generator at 
$12^{\circ }$ or 
$16^{\circ }$ to the freestream created an oblique shock which impinged on a boundary layer over a flat plate to induce flow separation. The flow field was examined using simultaneous measurements of wall static pressure, heat transfer and schlieren visualisation. Measured heat transfer along the flat plate without the shock impingement indicated that the boundary layer remained laminar for all flow conditions. The shock impingement flow field was successfully established within the facility test duration. The onset of separation was observed by a rise in wall pressure and a decrease in heat transfer at the location corresponding to the stem of the separation shock. Downstream of this initial rise, an increased pressure and higher heating loads were observed. The heat-transfer levels also indicated an immediate boundary layer transition due to the shock impingement. The separation data of the present work showed good agreement with our previous work on shock impingement on heated walls (Chang et al., J. Fluid Mech., vol. 908, 2021, pp. 1–13). A comparison with the previous scaling indicated that the separation also relates to the pressure ratio and the wall temperature parameter.
Elevated wall temperatures and impinging shock interactions are prevalent features in hypersonic flight. Currently, there is a lack of literature regarding experimental studies examining both features in a flight-representative environment. This work details hot-wall, hypersonic, impinging shock/boundary-layer interaction experiments performed in the T4 Stalker Tube. The model configuration was a two-dimensional heated flat plate and a shock generator. The surface of the graphite flat plate was resistively heated to a mean temperature from 
$T_w=298\ \textrm {K}$ to 
$T_w\approx 675\ \textrm {K}$ during an experimental run. An oblique shock, generated by a plate that was inclined at 
$10^{\circ }$ or 
$12^{\circ }$ to the free stream, was impinged on the heated flat plate to induce boundary layer separation. The primary flow condition produced Mach 7 flight-equivalent nozzle-supply enthalpy with a unit Reynolds number of 
$4.93\times 10^6\ \textrm {m}^{-1}$. More flow conditions with lower unit Reynolds numbers and flow enthalpies were considered to examine flow separation characteristics. Schlieren and infrared thermography captured the flow field and the wall temperature distribution, respectively. The results showed that the size of the flow separation grew with a higher 
$T_w$ and a lower unit Reynolds number. Moreover, the scaled separation of the present data showed a high discrepancy with existing separation correlations developed from a supersonic impinging shock and a hypersonic compression ramp, mainly due to the higher shock strength. Instead, the present data followed a scaling law that includes the pressure ratio across the impinging shock with a slight dependence on the wall temperature ratio.
We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band (
${\sim}60\%$
), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.
