scholarly journals Study on the Burning of a Fuel Drop in Heated and Pressurized Air Stream : 2nd Report Empirical Formulas Concerning the Burning Rate the Flame Shape

1969 ◽  
Vol 35 (275) ◽  
pp. 1503-1513
Author(s):  
Hiroshi SAMI ◽  
Mitsunobu OGASAWARA
1933 ◽  
Vol 16 (6) ◽  
pp. 911-923 ◽  
Author(s):  
Hudson Hoagland

1. Adaptation of tactile receptors in the skin of the frog to excitation by an intermittent jet of air is measured and correlated with certain properties of a series of notched discs used to interrupt the air stream. 2. Adaptation in fifteen cases is found to be described by either one of two empirical formulas, or t = -k log f + C, for nine preparations t = a f-b, for six preparations where f is the per cent frequency at time t and -k and -b are constants defining the rate of adaptation.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
R. Sreenivasan ◽  
Sumit Kumar Koli ◽  
Vasudevan Raghavan

Investigation of the influence of coflow and partial air premixing on liquid petroleum gas (LPG) flames in a lab-scale co-flow burner is presented. Primary air is supplied along with LPG in the inner core, and secondary air is supplied through the annulus region of the burner. Digital images are analyzed to study the flame shape, color, height, radius, and qualitative laminar flame speed. Concentrations of product gases and emission species are measured using a digital gas analyzer. Results indicate that in a dual air stream configuration, the partial premixing is optimum at % primary air value of around 45%.


2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Vaibhav Kumar Sahu ◽  
Vasudevan Raghavan ◽  
Daniel N. Pope ◽  
George Gogos

A numerical study of steady burning of spherical ethanol particles in a spray environment is presented. A spray environment is modeled as a high temperature oxidizer stream where the major products of combustion such as carbon dioxide and water vapor will be present along with reduced amounts of oxygen and nitrogen. The numerical model, which employs variable thermophysical properties, a global single-step reaction mechanism, and an optically thin radiation model, has been first validated against published experimental results for quasi-steady combustion of spherical ethanol particles. The validated model has been employed to predict the burning behavior of the ethanol particle in high temperature modified oxidizer environment. Results show that based on the amount of oxygen present in the oxidizer the burning rate constant is affected. The ambient temperature affects the burning rate constant only after a sufficient decrease in the oxygen content occurs. In pure air stream, ambient temperature variation does not affect the evaporation constant. Results in terms of burning rates, maximum temperature around the particle, and the evaporation rate constants are presented for all the cases. The variation of normalized Damköhler number is also presented to show the cases where combustion or pure evaporation would occur.


Author(s):  
Amir Mahdi Tahsini

The influence of the inlet swirling flow on the regression rate of the fuel in the combustion chamber of the solid fuel ramjet is investigated in this study using numerical simulations. The finite-volume solver of the compressible turbulent reacting flow is developed to study the flow field where the burning rate is computed using the conjugate heat transfer method for the solid fuel. The correlation is found for the maximum regression rate versus an imposed inlet swirl when the linear distribution of the circumferential velocity is applied at the inlet stream. Although the regression rate augmentation is considerable due to the swirling flow field in the combustor, it is shown that the swirl is effective if is applied near the shear layer of the backstep flow in the combustor. The modified swirler with short blades is suggested to be used in solid fuel ramjets to increase the regression rate of the fuel and improve the performance, but with lower pressure loss.


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