This study investigates the influence of multiple jet parameters on the flow field of translating impinging inclined water jets. We conducted full-scale stereoscopic particle image velocimetry and pressure measurements and three-dimensional computational fluid dynamics simulations for Reynolds numbers in the range of $Re = 23{,}000{-}43{,}750$. Considering the complex mechanism of a translating impinging jet, a good concordance is observed between the experimental and numerical results. The translation-to-jet velocity ratio ($R$) is identified as a critical parameter in determining whether the jet flow predominantly exhibits impinging characteristics or behaves as a jet in cross-flow. It is found that, for $R \gt 0.22$, jet impingement is minimal. The stand-off distance to nozzle diameter ratio ($H/D$) determines the relative influence of the cross-flow on the jet flow. The effect of $H/D$ is similar to a stationary impinging jet, with the potential core extending up to $H/D \approx 4$, but entrainment is enhanced by the relative cross-flow. For an inclined jet, i.e. jet angle $\theta \neq 90^{\circ}$, the direction of the jet, either backward or forward, governs the deflection of the flow. Higher pressures are recorded for a backward directed jet compared with a forward directed jet for supplementary angles.

The objective of maintaining the cleanliness of the multi-segment disk amplifier in Shenguang-II (SG-II) is to reduce laser-induced damage for optics. The flow field of clean gas, which is used for the transportation of contaminant particles, is a key factor affecting the cleanliness level in the multi-segment disk amplifier. We developed a gas–solid coupling and three-dimensional flow numerical simulation model. The three-dimensional and two-phase flow model is verified by the flow-field smog experiment and the particle concentration measurement experiment with the 130-disk amplifier in SG-II. By optimizing the boundary conditions with the same flow rate, the multi-inlet vector flow scheme can not only effectively reduce the purging time, but also prevent the reverse diffusion of contaminant particles in the multi-segment disk amplifier and the deposition of contaminant particles on the surface of the Nd:glass.

High levels of larval mortality are a significant barrierto the artificial mass production of Pacific bluefin tuna (Thunnusorientalis). Mortality may occur when larvae sink and comeinto contact with the bottom of the rearing tank during the first10 days after hatching. We evaluated the effect of flow controlby aeration on the survival of T. orientalis larvae.These larvae were held in 500-L tanks in which the aeration ratewas varied during the night. Larval survival increased with airsupply. We documented the cross-sectional flow pattern and gravitationalsinking velocities of larvae to assess the correlation between survivaland circulation patterns in the tank. The sinking velocity of T. orientalis larvaeat night increased with larval body density, which varied with swimbladdervolume. Larvae with uninflated swimbladders sank significantly fasterthan larvae with inflated swimbladders. Both water circulation speedand survival increased at higher aeration rates. Our results suggestthat aeration rates >900 ml min–1 may increase larval survival bycounteracting sinking.

Walking crabs move their eyes to compensate for retinal image motion only during rotation and not during translation, even when both components are superimposed. We tested in the rock crab, Pachygrapsus marmoratus, whether this ability to decompose optic flow may arise from topographical interactions of local movement detectors. We recorded the optokinetic eye movements of the rock crab in a sinusoidally oscillating drum which carried two 10-deg wide black vertical stripes. Their azimuthal separation varied from 20 to 180 deg, and each two-stripe configuration was presented at different azimuthal positions around the crab. In general, the responses are the stronger the more widely the stripes are separated. Furthermore, the response amplitude depends also strongly on the azimuthal positions of the stripes. We propose a model with excitatory interactions between pairs of movement detectors that quantitatively accounts for the enhanced optokinetic responses to widely separated textured patches in the visual field that move in phase. The interactions take place both within one eye and, predominantly, between both eyes. We conclude that these interactions aid in the detection of rotation.