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Showing 1 to 20 of 47 for “"air injection"”.
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Air Injection Technique to Mitigate Liquefaction beneath Shallow Foundations
… structures on shallow foundations can suffer. Air injection technique has the potential to improve the soil supporting new and existing structures. There is, however, little research on its application and performance beneath existing shallow foundations. The aim of this research was to provide …
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Suppression of premixed combustion dynamics utilizing microjet air injection
… instabilities through the use of microjet air injection. This was done by building upon a previous combustor setup to allow the installation of several new diagnostic capabilities and the new microjets.
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Optimization of Air-injection Spargers for Column Flotation Applications
… in a pulp. To achieve this process separation an air sparging device, which is required to produce bubbles in the flotation cell is required. In column flotation operations, Sparger sparging devices are employed in column flotation operations to generate small bubbles into the cell with the aim to …
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The effects of secondary air injection on particulate matter emissions
… to investigate the effects of secondary air injection (SAI) on particulate matter (PM) emissions. SAI was developed to reduce hydrocarbon (HC) emissions and has been shown to be effective as a strategy to reduce HC emissions at cold-start. In general, cold-start emissions have become an …
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Effects of secondary air injection during cold start of SI engines
… in the exhaust port, manifold, and catalyst. The injection of air into the exhaust system therefore could be an effective way to utilize additional thermal and chemical energy available in the exhaust gas. This study was initiated to investigate the thermal and chemical processes associated with …
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Suppression of thermoacoustic instabilities in a swirl combustor through microjet air injection
… and the potential for using secondary air injection to passively suppress combustion instability. Microjets inject air into the combustion chamber in the flame anchoring zone. These microjet injectors attempt to modify the flow field so as to break the feedback mechanism between the …
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Air injection in axial compressors : modeling experimental validation, and control of instabilities
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999.
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Effect of Passive Clean Air Injection Into the Wake Region of a Moving Ground Vehicle
… of the vehicle. To ensure high velocity fluid injection, a venturi shaped roof was implemented with an inlet size of 352mm x 12.7mm, and 2 outlets of size 88.011mm x 25.4mm resulting in an area of 4,470.959 for both inlet and outlet to maintain conservation of mass and not increase the pressure …
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Experimental Investigation of In Situ Combustion for Heavy Oils at Low Air Flux
… within the reservoirs is a must. Sufficient air must be supplied to maintain the propagating combustion front in the carbon oxide forming mode otherwise unfavorable low temperature oxidation reactions will consume oxygen and not mobilize oil. When this happens, the combustion process is …
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Heat transfer in upward flowing two-phase gas-liquid mixtures. An experimental study of heat transfer in two-phase gas-liquid mixtures flowing upwards in a vertical tube with liquid phase being driven by a pump or air injection.
… transfer coefficient was measured using either air to lift the liquid (air-lift system) or a mechanical pump. The heat transfer coefficient results have been extensively studied and compared with other workers' results. An attempt was made to correlate the present heat transfer data in …
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Rates of vertical mixing, gas exchange, and new production : estimates from seasonal gas cycles in the upper ocean near Bermuda
… production. In the winter mixed layer, air injection produces argon supersaturation despite high gas exchange rates. During spring and summer, radiative heating, air injection, and an upward argon flux create an even larger supersaturation in the mixed layer. In the seasonal thermocline, …
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Development of a Concept for Forced Response Investigations
… to improve performance and lower weight of aircraft engines, modern compressor blades become thinner and lighter but higher loaded resulting in an increased vulnerability towards flutter. This trend is further aggravated through blisk designs that diminish structural damping and therewith …
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Physics-based flame dynamics modeling and thermoacoustic instability mitigation
… scales. A passive control strategy involving injection of steady air ow near the step in the cross-stream or streamwise directions were tested. Both injection configurations were able to suppress the instability under some operating conditions at which the unsteady interactions between the …
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Bubble dynamics on structured surface in microchannel
… behavior of a single bubbles created by air injection on micropillar array was presented. Single 10-30 [mu]m injection holes were fabricated on micropillar array surfaces by laser cutter. The experimental results show that structured surfaces have higher bubble departure sizes than that …
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Characterization of air-sea gas exchange processes and dissolved gas/ice interactions using noble gases
… The processes of vertical mixing, gas exchange, air injection, and radiative heating are investigated using a 2 year time-series of the noble gases, temperature, and meteorological data from Station S near Bermuda, coupled with a 1- dimensional upper ocean mixing model to simulate the physical …
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Flame front imaging and ignition performance of ultra-compact trapped-vortex combustor
… was investigated at atmospheric pressure, with air injection temperatures of 25° and 10°C, using a conventional spark igniter and an experimental plasma igniter. At lean operating conditions, plasma ignition exhibited up to a 45% reduction in Eign, although negligible improvements were observed …
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Hypersonic nonequilibrium flow over an ablating teflon surface
A complex chemical system of teflon/air mixture over an axisymmetric decoy at hypersonic reentry flight conditions has been analyzed by using the nonequilibrium viscous shock-layer method. The equilibrium catalytic wall boundary condition was used to obtain the species concentration at the wall. …
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Transpiration cooling of a cylinder in crossflow : an experimental investigation
Experiments have been carried out in air on a two-inch diameter porous cylinder to determine the effect of air injection on heat transfer from a cylinder in crossflow. The Reynolds number based on cylinder diameter and free stream conditions was varied from 31,200 to 119,000 for the dimensionless …
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