Data of compressible multi-material flow simulations utilizing an efficient bimaterial Riemann problem solver.

This paper presents fluid dynamics simulation data associated with two test cases in the related research article [1]. In this article, an efficient bimaterial Riemann problem solver is proposed to accelerate multi-material flow simulations that involve complex thermodynamic equations of state and strong discontinuities across material interfaces. The first test case is a one-dimensional benchmark problem, featuring large density jump (4 orders of magnitude) and drastically different thermodynamics relations across a material interface. The second test case simulates the nucleation of a pear-shaped vapor bubble induced by long-pulsed laser in water. This multiphysics simulation combines laser radiation, phase transition (vaporization), non-spherical bubble expansion, and the emission of acoustic and shock waves. Both test cases are performed using the M2C solver, which solves the three-dimensional Eulerian Navier-Stokes equations, utilizing the accelerated bimaterial Riemann solver. Source codes provided in this paper include the M2C solver and a standalone version of the accelerated Riemann problem solver. These source codes serve as references for researchers seeking to implement the acceleration algorithms introduced in the related research article. Simulation data provided include fluid pressure, velocity, density, laser radiance and bubble dynamics. The input files and the workflow to perform the simulations are also provided. These files, together with the source codes, allow researchers to replicate the simulation results presented in the research article, which can be a starting point for new research in laser-induced cavitation, bubble dynamics, and multiphase flow in general.

Shock waves generated by toroidal bubble collapse are imperative for kidney stone dusting during Holmium:YAG laser lithotripsy.

Holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy (LL) has been the treatment of choice for kidney stone disease for more than two decades, yet the mechanisms of action are not completely clear. Besides photothermal ablation, recent evidence suggests that cavitation bubble collapse is pivotal in kidney stone dusting when the Ho:YAG laser operates at low pulse energy (Ep) and high frequency (F). In this work, we perform a comprehensive series of experiments and model-based simulations to dissect the complex physical processes in LL. Under clinically relevant dusting settings (Ep = 0.2 J, F = 20 Hz), our results suggest that majority of the irradiated laser energy (>90 %) is dissipated by heat generation in the fluid surrounding the fiber tip and the irradiated stone surface, while only about 1 % may be consumed for photothermal ablation, and less than 0.7 % is converted into the potential energy at the maximum bubble expansion. We reveal that photothermal ablation is confined locally to the laser irradiation spot, whereas cavitation erosion is most pronounced at a fiber tip-stone surface distance about 0.5 mm where multi foci ring-like damage outside the thermal ablation zone is observed. The cavitation erosion is caused by the progressively intensified collapse of jet-induced toroidal bubble near the stone surface (<100 µm), as a result of Raleigh-Taylor and Richtmyer-Meshkov instabilities. The ensuing shock wave-stone interaction and resultant leaky Rayleigh waves on the stone surface may lead to dynamic fatigue and superficial material removal under repeated bombardments of toroidal bubble collapses during dusting procedures in LL.

Dissimilar cavitation dynamics and damage patterns produced by parallel fiber alignment to the stone surface in holmium:yttrium aluminum garnet laser lithotripsy.

Recent studies indicate that cavitation may play a vital role in laser lithotripsy. However, the underlying bubble dynamics and associated damage mechanisms are largely unknown. In this study, we use ultra-high-speed shadowgraph imaging, hydrophone measurements, three-dimensional passive cavitation mapping (3D-PCM), and phantom test to investigate the transient dynamics of vapor bubbles induced by a holmium:yttrium aluminum garnet laser and their correlation with solid damage. We vary the standoff distance (SD) between the fiber tip and solid boundary under parallel fiber alignment and observe several distinctive features in bubble dynamics. First, long pulsed laser irradiation and solid boundary interaction create an elongated "pear-shaped" bubble that collapses asymmetrically and forms multiple jets in sequence. Second, unlike nanosecond laser-induced cavitation bubbles, jet impact on solid boundary generates negligible pressure transients and causes no direct damage. A non-circular toroidal bubble forms, particularly following the primary and secondary bubble collapses at SD = 1.0 and 3.0 mm, respectively. We observe three intensified bubble collapses with strong shock wave emissions: the intensified bubble collapse by shock wave, the ensuing reflected shock wave from the solid boundary, and self-intensified collapse of an inverted "triangle-shaped" or "horseshoe-shaped" bubble. Third, high-speed shadowgraph imaging and 3D-PCM confirm that the shock origins from the distinctive bubble collapse form either two discrete spots or a "smiling-face" shape. The spatial collapse pattern is consistent with the similar BegoStone surface damage, suggesting that the shockwave emissions during the intensified asymmetric collapse of the pear-shaped bubble are decisive for the solid damage.

Numerical simulation data of an elongated cavitation bubble induced by long-pulsed laser.

The simulation data presented in this paper describes the formation and growth of an elongated bubble induced by a long-pulsed laser. The simulation is performed using the M2C solver, which is a recently developed three-dimensional finite volume Navier-Stokes CFD solver. The solver is used to simulate the fluid dynamics of the liquid water, the laser radiation, the laser-induced vaporization, and the fluid dynamics of the bubble after its formation. The data presented in this paper corresponds to a representative case of the cavitation induced by a narrow Gaussian beam (cf. [1]). Simulation data include laser radiance, fluid velocity, pressure, temperature, and bubble dynamics. The input files and the workflow to perform this simulation are also provided. With the information provided in this paper, researchers can repeat this simulation, and use it as a starting point to study related problems involving laser-induced cavitation, continuous vaporization, and bubble dynamics in general.

Numerical simulation data of bubble-structure interactions in near-field underwater explosion.

The simulation data presented in this paper describes the interaction between a thin-walled aluminum cylinder and a gas bubble in a near-field underwater explosion. The simulation is performed using the AERO-F/S solvers. The finite element AERO-S solver is used to simulate the structural dynamics of the cylinder, including its yielding and collapse. The AERO-F solver is used to simulate the fluid dynamics of the explosion bubble, the surrounding liquid water, and the air inside the cylinder. The two solvers are coupled using an embedded boundary method and the FInite Volume method with Exact two-material Riemann problems (FIVER). The data presented in this paper corresponds to a representative case with initial pressure p 0 = 12.5 MPa inside the bubble (cf. [1]). Simulation data include structural stress and deformation, fluid velocity, pressure and bubble dynamics. The input files and the workflow to perform this simulation are also provided. With the information provided in this paper, researchers can repeat this simulation, and use it as a starting point to study related problems involving cavitation bubbles, underwater explosion, and fluid-structure interaction in general.

Sulfamethoxazole removal from mariculture wastewater in moving bed biofilm reactor and insight into the changes of antibiotic and resistance genes.

Antibiotics are widely dosed in mariculture sector, resulting in substantial antibiotics residues. Hence, mariculture wastewater is urgent to be treated before discharging. In this study, the anoxic/oxic moving bed biofilm reactor (A/O-MBBR) was used to treat the wastewater containing sulfamethoxazole (SMX) from mariculture, SMX removal mechanism and the variation of antibiotic-resistant genes (ARGs) were investigated. The results showed that 22%-33% of SMX was removed by the bioreactor, where a small amount of SMX was adsorbed and stored by the extracellular polymers and most of SMX (>80%) was biodegraded in the anoxic tank. Occurrence of nitrate in anoxic condition was conducive to SMX degradation. Pseudomonas, Desulfuromusa, and Methanolobus species, as well as microbial catalase contributed to the SMX biotransformation. Quantitative PCR analysis of ARGs (sul1, sul2 and int1) and mRNA (sul1, sul2) showed that SMX enriched SMX-related ARGs and enhanced the expression of corresponding genes. Most of ARGs finally were discharged with effluent. Hence, the effluent from biologically based processes treating mariculture wastewater still contained antibiotics residue and resistance genes, which should be further controlled by suitable techniques.