Anti-PIV type 1 Polyclonal antibody

Large-eddy simulation has been increasingly applied to internal combustion engine flows because of their improved potential to capture the spatial and temporal evolution of turbulent flow structures compared with Reynolds-averaged Navier Stokes simulation. Furthermore, large-eddy simulation is universally recognized as capable of simulating highly unsteady and random phenomena, which drive cycle-to-cycle variability and cycle-resolved events such as knocks and misfires. To identify large-scale structure fluctuations, many methods have been proposed in the literature. This article describes the application of several analysis methods for the comparison between different datasets (experimental or numerical) and the identification of large-structure fluctuations. The reference engine is the well-known TCC-III single-cylinder optical unit from the University of Michigan and GM Global R&D center; the analyses were carried out under motored engine conditions. A deep analysis of in-cylinder gas dynamics and flow structure evolution was performed by comparing the experimental results (particle image velocimetry of the velocity fields) with a dataset of consecutive large-eddy simulation cycles on four different cutting planes at engine-relevant crank angle positions. Phase-dependent proper orthogonal decomposition was used to obtain further conclusions regarding the accuracy of the simulation results and to apply conditional averaging methods. A two-point correlation and an analysis of the tumble center are proposed. Finally, conclusions are drawn to be used as guidelines in future large-eddy simulation analyses of internal combustion engines.

Droplet heat transfer in between parallelly located superhydrophobic plates is examined. The thermal field inside the droplet is predicted by adopting the experimental conditions. The influence of plates spacing (heights) on the thermal response of the droplet fluid is investigated. Particle injection velocimetry (PIV) is used to validate the velocity predictions. We demonstrated that predictions of flow velocity are in agreement with those of the PIV results. The heating of the droplet in the absence of the top plate gives four circulation cells in the droplet. Once the top superhydrophobic plate is introduced, the flow structure alters, and the number of the circulating structures reduces to two. Lowering the height of the plates increases the droplet Laplace pressure while modifying the fluid flow and thermal behavior. The Bond number is lower than one for all the cases considered; hence, demonstrating that the Marangoni force affects the formation of the circulation cells. The cells redistribute the heated fluid in the droplet interior, which is clearly apparent for the plates with small heights. Temperature enhancement in the droplet bottom section is attributed to the flow current formed due to heat diffusion. The Nusselt number corresponding to the bottom plate increases as the plate heights reduces; however, the opposite is true for that corresponding to the top plate.