We analyzed the generation characteristics of hydrate in a reaction kettle and established a convection–diffusion model of temperature and carbon dioxide. The concentration of liquid carbon dioxide and carbon dioxide dissolved in water were geometrically modeled according to the density of carbon dioxide and its solubility in water under varying temperature and pressure. The distributions of temperature

In this paper, the highly deformed bubbles produced in the regime of bubbling with coalescence are studied systematically, starting from their formation up to their collapse dynamics. We investigate the bubbling dynamics by performing experiments with various liquids (ultrapure water and silicone fluids), gas flow rates (5 ∼ 300 ml/min) and nozzle radii (0.18 ∼ 0.55 mm). The evolution of the coalescing

After the biogas is upgraded to CH4, a waste stream (tail biogas) is obtained, which contains methane in the order of few to tens vol.%. However, the composition of tail biogases can be unstable, therefore, safety should be maintained during the onsite combustion processes. Accordingly, a process control system with various sensors needs to be introduced. This study aims to analyze the experimental

Having the advantage of durability (simple in structure without mechanical pump), two-phase natural circulation (TPNC) loops were widely used, but still limited by its inherent instability that may lead to evaporator dry out (boiling crisis). Till now, the mechanism of the TPNC instability are not fully understood. In our previous experiment in a TPNC close loop with a singly connected accumulator

Although the effect of pressure on the characteristics of laminar diffusion flame has been extensively studied, there is need of simple similarity correlations for flame shape and radiation fraction, which can be useful for application to turbulent flows and fire safety. In this paper, similarity analysis for flow and soot models is developed, where non-dimensional parameters were defined for the flame

A PIV-based system has been set-up for the simultaneous measurement of the local propagation velocity and the flame stretch of laminar jet premixed flames. The contributions of the flame front curvature and the strain rate of the fresh gas flow to the flame stretch are separately discussed. Laminar jet flames of methane-air lean mixtures have been studied with a secondary flame in a coflow configuration

Selective Catalytic Reduction is a key technology for reducing nitrogen oxide (NOx) emissions of diesel engines, which requires the injection of urea–water solution (UWS) into the hot exhaust gas. The main objective of this paper is the development of a methodology for predicting the evaporation of urea-water sprays. For this reason a generic experiment was conducted in order to provide validation

Hydrodynamic characteristics and the corresponding heat transfer performance are important features of hydrocarbons flow in regenerative active cooling systems. The main objective of this study is to clarify the intrinsic relationship between the hydrodynamic and heat transfer characteristics in a horizontal stainless mini-tube. Experiments were conducted using pure hydrocarbons of cyclohexane and

The dynamic behaviour of periodically oscillating laminar premixed acetylene-air flames in a micro-channelled combustor consisting of an array of five planar rectangular channels was found to be influenced by the equivalence ratio and flow-rate of the continuously and steadily injected premixed fuel charge. Three distinct flame stages were observed — planar, chaotic and trident, which were strongly

The effect of viscosity on the behavior of a non-equilibrium bubble is investigated experimentally, in two scenarios; firstly, when the bubble is generated in the bulk of the fluid (termed as “free-field” bubble) and secondly when the bubble is generated near a free-surface (termed as “free-surface” bubble). The bubble is created using a low-voltage spark circuit and its dynamics is captured using

Recent theoretical and numerical studies predict the Moffatt eddies near the interface-wall intersection in a two-fluid flow. The current work provides the first experimental evidence of this phenomenon of fundamental interest. It also reveals a jump of the azimuthal velocity at the interface which can be important for vortex bioreactors. The rotating lid drives a two-fluid flow in a vertical cylindrical

This paper reports an experimental study of single Taylor bubbles rising in stagnant water-glycerin mixtures inside slightly deviated cylindrical tubes. The inclination angles studied were 0°, 2.5°, 5°, 7.5°, 10° and 15° from the vertical. The rise bubble velocity and the shape of the bubbles at two vertical orthogonal planes that intersect at the tube axis were measured by using a pulse-echo ultrasonic

Biofuels in the form of water-in-oil (W/O) emulsions are a promising substitution for hydrocarbon fuels, mainly thanks to the micro-explosion phenomenon that occurs under strong heating. Micro-explosion is the atomization of a W/O emulsion drop into daughter droplets because of the water embedded droplets phase change. This atomization leads to the reduction of pollutants and unburnt hydrocarbons emissions

A method for the experimental characterization of the velocity, hydrodynamic pressure, and acoustic generation in a subsonic (ReH=25,500), three-dimensional, turbulent wall jet is presented. An acoustic analogy formulated for the turbulent wall jet shows that the far-field acoustics relate to the Reynolds stress fluctuations of the velocity field or the product of the hydrodynamic pressure fluctuations