CFD Modeling of Low Temperature Ignition Processes From a Nanosecond Pulsed Discharge at Quiescent Conditions

2021 ◽  
Author(s):  
Vyaas Gururajan ◽  
Riccardo Scarcelli ◽  
Sayan Biswas ◽  
Isaac Ekoto
Keyword(s):  
Low Temperature ◽  
First Principles ◽  
Numerical Approach ◽  
Cfd Modeling ◽  
Reacting Flow ◽  
Temperature Plasma ◽  
Flow Solver ◽  
Detailed Chemistry ◽  
Equilibrium Plasma ◽  
Non Equilibrium

Abstract Recent interest in non-equilibrium plasma discharges as sources of ignition for the automotive industry has not yet been accompanied by the availability of dedicated models to perform this task in computational fluid dynamics (CFD) engine simulations. The need for a low-temperature plasma (LTP) ignition model has motivated much work in simulating these discharges from first principles. Most ignition models assume that an equilibrium plasma comprises the bulk of discharge kernels. LTP discharges, however, exhibit highly non-equilibrium behavior. In this work, a method to determine a consistent initialization of LTP discharge kernels for use in engine CFD codes like CONVERGE is proposed. The method utilizes first principles discharge simulations. Such an LTP kernel is introduced in a flammable mixture of air and fuel, and the subsequent plasma expansion and ignition simulation is carried out using a reacting flow solver with detailed chemistry. The proposed numerical approach is shown to produce results that agree with experimental observations regarding the ignitability of methane-air and ethylene-air mixtures by LTP discharges.

scholarly journals Non-equilibrium melting processes of silicate melts with different silica content at low-temperature plasma

2015 ◽  
Vol 652 ◽  
pp. 012022
Author(s):  
V Vlasov ◽  
G Volokitin ◽  
N Skripnikova ◽  
O Volokitin ◽  
V Shekhovtsov ◽  
...  
Keyword(s):  
Low Temperature ◽  
Silica Content ◽  
Silicate Melts ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Non Equilibrium

scholarly journals Flow reactor studies of non-equilibrium plasma-assisted oxidation of n -alkanes

2015 ◽  
Vol 373 (2048) ◽  
pp. 20140344 ◽  
Author(s):  
Nicholas Tsolas ◽  
Jong Guen Lee ◽  
Richard A. Yetter
Keyword(s):  
Low Temperature ◽  
Fuel Consumption ◽  
Flow Reactor ◽  
Negative Temperature ◽  
Intermediate Species ◽  
Chain Branching ◽  
Temperature Changes ◽  
Equilibrium Plasma ◽  
Elevated Pressures ◽  
Non Equilibrium

The oxidation of n -alkanes (C 1 –C 7 ) has been studied with and without the effects of a nanosecond, non-equilibrium plasma discharge at 1 atm pressure from 420 to 1250 K. Experiments have been performed under nearly isothermal conditions in a flow reactor, where reactive mixtures are diluted in Ar to minimize temperature changes from chemical reactions. Sample extraction performed at the exit of the reactor captures product and intermediate species and stores them in a multi-position valve for subsequent identification and quantification using gas chromatography. By fixing the flow rate in the reactor and varying the temperature, reactivity maps for the oxidation of fuels are achieved. Considering all the fuels studied, fuel consumption under the effects of the plasma is shown to have been enhanced significantly, particularly for the low-temperature regime ( T <800 K). In fact, multiple transitions in the rates of fuel consumption are observed depending on fuel with the emergence of a negative-temperature-coefficient regime. For all fuels, the temperature for the transition into the high-temperature chemistry is lowered as a consequence of the plasma being able to increase the rate of fuel consumption. Using a phenomenological interpretation of the intermediate species formed, it can be shown that the active particles produced from the plasma enhance alkyl radical formation at all temperatures and enable low-temperature chain branching for fuels C 3 and greater. The significance of this result demonstrates that the plasma provides an opportunity for low-temperature chain branching to occur at reduced pressures, which is typically observed at elevated pressures in thermal induced systems.

scholarly journals Influence of non-equilibrium low-temperature plasma on consumer characteristics of spunmelt material

2020 ◽  
Vol 64 (11) ◽  
pp. 143-148
Author(s):  
Maria S. Lisanevich ◽  
◽  
Reseda Yu. Galimzyanova ◽  
Rustem G. Ibragimov ◽  
◽  
...  
Keyword(s):  
Low Temperature ◽  
Gas Flow ◽  
Rapid Development ◽  
Low Temperature Plasma ◽  
Normal Range ◽  
Temperature Plasma ◽  
Environmental Friendliness ◽  
Material Stiffness ◽  
Surgical Gowns ◽  
Non Equilibrium

Nonwovens (nonwovens) are widely used in medicine, for the manufacture of medical linen, sanitary and hygienic items, medical clothing, surgical materials (including dressings). The rapid development of the clothing market requires domestic manufacturers to be competitive not only through new products and technologies, but also new sensations for the consumer, provided that the price is competitive. According to medical workers, disposable surgical gowns based on spunmelt materials give a feeling of discomfort during use. One and relatively new method for modifying nanomaterials is treatment with nonequilibrium low-temperature plasma (NLTP). The main advantage of this type of material modification is the environmental friendliness of the method, as in the process of processing aqueous solutions of chemicals are not used, as in the case of using special impregnations. Modern research of medical services. As a result of the work, it was revealed that the modification of NM NNTP allows you to change the NM for changes in surface, physical and mechanical, as well as consumer properties, while maintaining the strength characteristics. It is shown that after plasma treatment spunmelt materials increase such consumer characteristics as air permeability, hygroscopicity, while maintaining the strength during elongation; reduction of material stiffness during bending. It was also found that after the processing of NTPP, the electrification rate increases within the normal range, in GOST 12.1.045-84. Manufacturers are recommended to process spunmelt material with non-equilibrium low-temperature plasma on a high-frequency capacitive plasma installation with a power of Wp = 1.5 kW, processing time τ = 180 s and pressure P = 21.5 Pa. Use argon gas with a gas flow of 1500 cm3/min as a plasma-forming gas.

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