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Gravity currents produced from a full-depth lock release propagating at the base of a linearly stratified ambient are investigated by means of newly conducted three-dimensional high-resolution simulations in conjunction with corresponding two-dimensional simulations and laboratory experiments. A passive tracer is implemented in the simulations to quantitatively measure the energies associated with the current and the ambient. The density of heavy fluid within the lock is ρ C, the density in the ambient of depth H varies linearly from ρ b at the bottom to ρ 0 at the top, and the ambient has an intrinsic frequency N . Attention is focused on the initial slumping stage, during which the gravity currents propagate at a constant velocity V and the internal Froude number is defined as F r = V / N H . The dynamics of the subcritical gravity currents, i.e., F r 1 / π, are qualitatively different and are examined with the help of three-dimensional and two-dimensional high-resolution simulations. For the subcritical gravity currents, the flow is dominated by the internal wave, the Kelvin–Helmholtz vortices are inhibited, and the two-dimensional simulation agrees well with and serves as a good surrogate model for the three-dimensional simulation in the slumping stage. For the supercritical gravity currents, the Kelvin–Helmholtz vortices are pronounced and prone to breakup into three-dimensional structures in the slumping stage. On the one hand, for the supercritical gravity currents, the kinetic energy associated with the current and the potential energy associated with the ambient are accurately captured by the two-dimensional simulation. On the other hand, the transition distance for the slumping stage and dissipation rate in the system are underpredicted while the kinetic energy associated with the ambient and the potential energy associated with the current are overpredicted by the two-dimensional simulation for the supercritical gravity currents. Therefore, information derived from the two-dimensional simulation for the supercritical gravity currents must be treated with care. The high-resolution simulations in this study also complement the existing shallow-water formulation, which has been reported to agree well with the two-dimensional simulations with good physical assumptions and simple mathematical models.

Background: Splenic artery embolization (SAE) has been used as an adjunct to the nonsurgical treatment of blunt splenic injuries since 1981. It is imperative to define the role of SAE in the management of splenic trauma and to establish a guideline for its use. Methods: In this study, 39 consecutive patients with blunt splenic ruptures were evaluated. All the patients were treated according to the authors' protocol, which included SAE as an adjunct. Angiographic study was performed for patients with any of the following presentations: recurrent hypotension despite fluid resuscitation, significant hemoperitoneum or extravasation of contrast media on computed tomography, grade 4 or 5 splenic injury, or progressive need for blood transfusion. Laparotomy was reserved for patients with unstable hemodynamics or failure of SAE. Results: Four patients were excluded from the study, and 6 of the 35 remaining patients (male-to-female ratio, 22:13) received SAE. One of the six SAE patients underwent operation because of persistent hemorrhage after SAE. Nonoperative treatment was successful for 31 patients. Splenic artery embolization increased the success rate for nonsurgical management from 74% (26 of 35 patients) to 89% (31 of 35 patients). Conclusions: Judicious use of SAE for patients with blunt splenic injury avoids unnecessary surgery and expands the number of patients who can retain their spleen.