Direct numerical simulation (DNS), based on high-order numerical schemes, is used to study the effects of distributed pressure gradients on the redistribution of fluctuating kinetic energy in supersonic nozzle and diffuser flow with incoming fully developed turbulent pipe flow. Axisymmetric geometries and flow parameters have been selected such that shock waves are avoided and streamline curvature remains unimportant. Although mean extra rates of strain are quite small, strong changes in Reynolds stresses and their production/redistribution mechanisms are observed, in agreement with findings of Bradshaw (J. Fluid Mech., vol. 63, 1974, pp. 449–464). The central role of pressure–strain correlations in changing the Reynolds stress anisotropy is highlighted. A Green’s function-based analysis of pressure–strain correlations is presented, showing remarkable agreement with DNS data.

Direct numerical simulation (DNS) is used to explore similarities and differences between fully developed supersonic turbulent plane channel and axisymmetric non-swirling pipe flow bounded by isothermal walls. The comparison is based on equal friction Mach number, friction Reynolds number, Prandtl number, ratio of specific heats and viscosity exponent. The channel half-width and pipe radius are chosen to define the Reynolds numbers. To what extent and why mean flow quantities, second-order turbulence statistics and terms in the Reynolds stress equations coincide or diverge in both flows are investigated. The role of the fluctuating pressure in causing characteristic differences among correlations involving pressure fluctuations is identified via a Green-function-based analysis of the pressure field.

Aortic atresia is rare in the setting of a normally developed left ventricle with a ventricular septal defect. In this combination, as far as we know, it has been described only with concordant ventriculo-arterial connections, for which seven one-stage biventricular repairs have now been described. We describe here the case of a 3½-month-old male infant with a similar combination but with discordant ventriculo-arterial connections and severe pulmonary hypertension. It was the right ventricle which achieved normal size in this arrangement, presumably because of the ventricular septal defect. One-stage biventricular correction was accomplished, employing a single pulmonary allograft, aided by massive doses of Prostaglandin El. As far as we know this is the first report of the combination of aortic atresia, discordant ventriculo-arterial connections, a ventricular septal defect and balanced ventricles. We complement our surgical account, nonetheless, with a description of a comparable specimen from our anatomic museum.

Direct numerical simulation is used to investigate effects of heat release and compressibility on mixing-layer turbulence during a period of self-similarity. Temporally evolving mixing layers are analysed at convective Mach numbers between 0.15 and 1.1 and in a Reynolds number range of 15000 to 35000 based on vorticity thickness. The turbulence inhibiting effects of heat release are traced back to mean density variations using an analysis of the fluctuating pressure field based on a Green's function.

At the close of the Cyclops adventure Odysseus piously sacrifices to Zeus the ram that has carried him out of Polyphemus' cave. Yet the god spurns his offering and ponders instead the destruction of Odysseus' ships and their crews (ix 553–5):

These lines need explaining, as they present two difficulties, one formal, the other thematic. How can Odysseus know what Zeus is pondering? As a first-person narrator Odysseus assumes temporarily the role of the epic poet, yet without being given the latter's omniscience. He retains therefore the restricted perspective of an epic character which precludes any precise knowledge of supernatural processes.