Milad Behzadi; Mohammad Farshchi
Volume 8, Issue 1 , April 2015, , Pages 9-18
Abstract
Dynamics of laminar premixed conical flame in acoustic-velocity field was studied via numerical simulation. Methane/air combustion was modeled using a single-step, irreversible reaction and diffusion phenomena with a simple but efficient method. First, the steady flame was obtained and its corresponding ...
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Dynamics of laminar premixed conical flame in acoustic-velocity field was studied via numerical simulation. Methane/air combustion was modeled using a single-step, irreversible reaction and diffusion phenomena with a simple but efficient method. First, the steady flame was obtained and its corresponding parameters were verified. Then this steady state solution was excited by modulation of the inlet velocity. After the initial transients, heat release rate of the flame kept fluctuating with the forced frequency. The response function for various modulation intensities and frequencies agrees satisfactorily with experiments. Also, like the experimental observations the flame wrinkles and the convex sections which convert to sharp edges travel from the base to the tip of the cone at the speed of the flow.
A. Rezaiha; M. Anbarloi; M. Farshchi
Volume 3, Issue 2 , January 2011, , Pages 23-30
Abstract
Although Pulsed Plasma Thruster (PPT) has first been utilized in a space mission in 1964 but after more than four decades, it is still a space rated technology which has performed various propulsion tasks from stationkeeping tasks to three-axis attitude control for a variety of former missions. With ...
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Although Pulsed Plasma Thruster (PPT) has first been utilized in a space mission in 1964 but after more than four decades, it is still a space rated technology which has performed various propulsion tasks from stationkeeping tasks to three-axis attitude control for a variety of former missions. With respect to the rapid growth inthe small satellite communityand the growing interest for smaller satellites in recent years, PPT is one of the promising electric propulsion devices for small satellites (e.g. CubeSats) as the following advantages: simplicity, lightweight, robustness, low power consumptions, low production costs and small dimensions. In spite of the fact thatthe issues relating to μPPT scaling have been investigated to a certain degree in recent years, it is felt that for an application on CubeSats this topic has to be investigated in greater detail for even smaller dimensions and better performance. Therefore a laboratory benchmark rectangular breech-fed pulsed plasma thruster (PPT) was designed, developed and successfully tested in a bell-type vacuum chamber at 10-6 mbar for the first time in west Asia (Iran). The PPT has been tested while the main capacitor, which is a 35 μF, 2.5 kV oil-filled capacitor, has been charged with a wide range of voltage, ranging from 250 V to 1750 V making the system stored energy range from less than 1 J to 60 J, producing the impulse bit varying from 30 μN-s to 1.3 mN-s. This work initiated a research program in Iran for working on PPTs and miniaturization of PPTs while increasing the performance parameters. The present paper reviews the PPT design and the development briefly.