The evolution of ocean temperature measurement systems is presented with a focus on the development and accuracy of two critical devices in use today (expendable bathythermographs and conductivity‐temperature‐depth instruments used on Argo floats). A detailed discussion of the accuracy of these devices and a projection of the future of ocean temperature measurements are provided. The accuracy of ocean temperature measurements is discussed in detail in the context of ocean heat content, Earth's energy imbalance, and thermosteric sea level rise. Up‐to‐date estimates are provided for these three important quantities. The total energy imbalance at the top of atmosphere is best assessed by taking an inventory of changes in energy storage. The main storage is in the ocean, the latest values of which are presented. Furthermore, despite differences in measurement methods and analysis techniques, multiple studies show that there has been a multidecadal increase in the heat content of both the upper and deep ocean regions, which reflects the impact of anthropogenic warming. With respect to sea level rise, mutually reinforcing information from tide gauges and radar altimetry shows that presently, sea level is rising at approximately 3 mm yr⁻¹ with contributions from both thermal expansion and mass accumulation from ice melt. The latest data for thermal expansion sea level rise are included here and analyzed.

Purpose: The purpose of this study is to quantify the relationship between the fluid flow and pressure drop for perforated plates. The homogenization of non-uniform fluid flows is often accomplished by passing the fluid through perforated plates. The underlying principle for the accomplishment of flow homogenization is a tradeoff of pressure drop for flow uniformity. Design/methodology/approach: The investigation, implemented by numerical simulation, is based on turbulent flow in pipes and across perforated plates. The approach is as follows: (a) to devise a model to determine pressure drop’s fluid flow information from a single-aperture, (b) to obtain this information for apertures of different shapes, (c) to determine this type of information for perforated plates situated in a circular pipe, (d) to compare the entire perforated-plate pressure drop with that for a single-aperture modular and (e) to analyze two identical perforated plates in series. Findings: The pressure drop results for the single-aperture modular model agreed very well with those for a whole perforated plate in a round pipe, therefore negating the need to simulate the more complex situation. In addition to the parametric study with aperture shape and Reynolds number, porosities (20-60 per cent) and plate thicknesses were also varied. The results obtained here compared favorably with experimental data. Originality/value: This work demonstrates an efficient method for analyzing and obtaining useful pressure drop information for perforated plates. For the first time, the porous media approach for modeling perforated plates is compared directly to complete, full-scale perforated plate applications and identical plates in series.

Turbulent fluid flows with a swirl occur in numerous engineering practice situations. Five widely recognized turbulence models were evaluated using experimental results. Among the RANS-based two-equation models, the SST κ–ω model proved to be the most effective. The predictions obtained from a LES turbulence model were slightly better, however there was an enormous difference in the CPU time. The CPU time needed for the LES solution was 155.3 days, whereas it was only 14.2 days for the SST κ–ω solution. In this light, it is believed that the SST κ–ω model is the most efficient of those investigated. An important input for the numerical simulation of turbulent flow and heat transfer is the turbulence intensity at the inlet of a solution domain. For the evaluation of turbulence models, use was made of the measured turbulence quantities from the verification experiments. More often, simulations are executed based on the uniform values of the turbulence intensity across the inlet. The errors in the heat transfer results due to this practice are evaluated and are shown to be significant.