Showing papers in "Experimental Thermal and Fluid Science in 2020"

TL;DR: In this article, a multi-channel gliding arc (MCGA) plasma was used to enhance ignition and combustion of ethylene fuel in a cavity-based scramjet combustor with an inflow speed of Ma − 2.92.

TL;DR: In this paper, the stability limits of theoretically-premixed ammonia-methane-air mixtures are measured for a wide range of ammonia additions in a laboratory-scale swirl burner.

TL;DR: In this article, the performance of modified heating surfaces consisting of metal foams of nickel (Ni) and copper (Cu) at saturation conditions was investigated, and the results showed that the metal foam surfaces provided a higher heat transfer coefficient compared to plain surfaces and prevented thermal overshoot at the onset nucleate boiling.

TL;DR: In this article, diesel engine exhausts from a common rail 3.0-L F1C diesel engine were analyzed at two different load conditions of the WLTC testing cycle downstream of both the diesel particulate filter (DPF) and selective catalytic reactor (SCR) to verify their effect on the characteristics of carbon particulate matter.

TL;DR: In this paper, the authors present a comprehensive analysis of wind characteristics using data obtained from two wind masts located at hillside and at the bottom of a canyon, and show that the mean wind speed, turbulence intensity, and wind power spectra cannot be predicted accurately using specifications or standards.

TL;DR: In this article, a systematic analysis of the effect of the geometry of biphilic patterns on bubble dynamics and consequently on the heat transfer processes occurring in pool boiling was performed using synchronized high-speed video and time-resolved thermography.

TL;DR: In this article, the authors performed a combined experimental and numerical study of the flame uniformity for a standard McKenna burner by investigating the spatially-resolved temperature and species concentrations in laminar CH4/air premixed flames.

TL;DR: In this paper, the experimental analysis of heat transfer distribution and friction features of a solar air heater that has a rough absorbent surface with a winglet type vortex generator has been made using liquid crystal thermography technique.

TL;DR: This work investigates the off-centered droplet impact on single-ridge superhydrophobic surfaces and focuses on the morphologic evolution and contact time, identifying six typical morphologic Evolution types as off- centered distance changes.

TL;DR: In this paper, the authors used two conventional high speed cameras to detect shock waves inside cavitating flow and estimated the amplitude of the shock wave front velocities and local pressure waves caused by cavitation cloud collapse.

TL;DR: In this paper, a general method for estimating the unsteady aerodynamic forces on elongated bodies in grid-generated turbulent flow was developed, where the key to this method is the identification of the one-wavenumber aerodynamic transfer function (ATF) of bluff sections.

TL;DR: In this paper, the authors presented the results of an experimental investigation into the water boiling heat transfer in a minichannel conduit vertically oriented with the upward flow, and the authors used a flow pattern map with the vapor quality as the abscissa versus the mass velocity as the ordinate.

TL;DR: In this paper, the authors studied the deformation of a cone-joint with applied potential, liquid flow rate and properties of the meniscus, and showed that the shape of the cone is also affected by flow rate.

TL;DR: In this paper, two concentric droplets consecutively impinging over a thin heated foil surface were carried out to compare the spread and heat transfer dynamics of a single drop, and drop-on-drop configurations using high speed imaging and infrared thermography.

TL;DR: In this paper, surface wettability plays a significant role on the dynamic characteristics of droplet impact, and the effect of surface Wettability is analyzed with the curvature ratios of 1.4, 0.43, and 0.26, respectively.

TL;DR: In this paper, the influence of the heating load, working fluid, fill ratio, and the evaporator surface design on thermosyphon thermal performance and associated instabilities was studied.

TL;DR: In this paper, an experimental study was conducted to investigate the condensation regime and pressure oscillation characteristics of vertical upward steam jet condensation with low mass flux, and four typical regimes were found, namely, chugging, detached oscillatory, detached cracked and secondary bubble impinged regimes.

TL;DR: In this article, the authors investigated bubble coalescence and departure in the boiling process and quantitatively obtained the variation of vapor bridge during the coalescence, and the oscillation of bubble radius in the rising period.

TL;DR: In this article, a novel approach to better understand the occurrence of micro-explosion is proposed, which consists on the identification of the drop triggering the atomization, called the trigger drop, and measure its properties (temperature, size and position within the emulsion drop) thanks to nonintrusive optical diagnostics.

TL;DR: In this article, a new experimental database of adverse-pressure-gradient (APG) turbulent boundary layers (TBLs) obtained through hot-wire anemometry and oil-film interferometry covering a momentum-loss Reynolds number 450 Re θ 23450 and Clauser pressure-gradient-parameter range up to β ≈ 2.4 is presented.

TL;DR: In this article, an open-source fused filament fabrication 3D printer was used to produce low-cost, porous polymer fixtures that are designed to alter bubble dynamics and improve the pool boiling heat transfer characteristics from flat copper surfaces.

TL;DR: In this article, a series of experiments on cylinders that have circular, square and rectangular cross sections were performed, and the authors found that the porous media applied to the circular cylinder had the most effect on the wake, and was observed in the wake generated by the most permeable material.

TL;DR: In this paper, the authors investigated the effect of vortex cavitation in diesel nozzles and its effects on spray characteristics by performing visualization experiments in scaled-up optical nozzle.

TL;DR: In this paper, a diabatic flow pattern map for accelerated two-phase capillary flows is presented, together with quantitative criteria for the calculation of the flow regime transitions, defining the physic limits for the bubble coalescence and break-up.

TL;DR: In this paper, the influence of wall superheat and the frequency of drop generation on the hydrodynamics and heat transport during the vertical coalescence of multiple successive drops impacting a hot wall are analyzed experimentally.

TL;DR: In this paper, a dyed water droplet was released on the substrate and a color high speed camera captured the details of the process including the interaction of the two like liquids, but with different colors.

TL;DR: In this paper, the authors investigated the dynamic behavior of foam flows, including flow regimes, their transitions and pressure profiles in relation to foam characteristics (foam holdup and wetness) at different surfactant concentrations.

TL;DR: In this article, the behavior of water drops in a continuous oil medium inside a centrifugal pump impeller working at eight operational conditions (up to 1200 rpm and 2.8 m3/h) with two-phase liquid-liquid flows was investigated.

TL;DR: In this article, the authors investigated the influence of sub-atmospheric pressure on multiscale heat transfer characteristics during liquid pool boiling and showed that the growth rate of dry spots is constant in time and has a nonmonotonic dependence on pressure.

TL;DR: In this article, a short splitter plate is placed on the upstream side of a circular cylinder to modify its incoming flow conditions and the wake-vortex patterns and to attenuate the aerodynamic forces.