Vaughn College of Aeronautics and Technology

About: Vaughn College of Aeronautics and Technology is a education organization based out in New York, New York, United States. It is known for research contribution in the topics: Gravitational microlensing & Planetary system. The organization has 727 authors who have published 708 publications receiving 14082 citations. The organization is also known as: College of Aeronautics.

Some aspects of the degradation of epoxide resins

Abstract: This paper contains a description of the use of gas chromatography to examine the pyrolytic degradation of epoxide resins. The method depends on the pyrolysis of the material by use of an electrically heated filament, the difficulties of the method are examined and attempts to overcome them are described. The pyrolytic degradation of a resin based on the glycidyl ether of bisphenol-A hardened with 1,2-diaminoethane and also triethylenetetraamine, is described. An attempt has been made to explain, in terms of possible degradation reactions, the actual compounds detected in the pyrolytic breakdown.

The reflexion of a plane shockwave from a heat-conducting wall

Abstract: The situation following reflexion of a discontinuous plane shockwave from a coplanar, heat-conducting wall is analysed by the method of matched asymptotic expansions. Temperature jump effects are included. Two terms of the outer expansion are calculated ((i) the 'ideal' inviscid, nonheat conducting solution; (ii) the displacement effect) as well as two terms of the inner series ((i) constant pressure thermal boundary layer; (ii) first correction term resulting from pressure and temperature changes due to the displacement effect). The results agree reasonably well with experimental observations and it appears that accommodation effects may account for some observations of reflected-shock trajectories.

The Laminar Diffusion Flame in Oseen Flow: The Stoichiometric Burke-Schumann Flame and Frozen Flow

Abstract: The Oseen approximation is used to study the behaviour of two initially separated gas streams which, when they are united, may form a combustible mixture. The limiting cases of small and large burning reaction time are dealt with for an irreversible fuel-oxidant chemical reaction, the former of these cases being identified with the Burke-Schumann flame. The half-plane problems encountered lead to integral equations of the Wiener-Hopf type. Their general solutions are obtained and yield a description of the field near to the flame or mixing zone in terms of simple functions. We consider the following problem. Two uniform parallel gas streams in a two dimensional (planar) steady flow field are initially separated by a thin diaphragm lying along the negative half of the x axis. The chemical composition of the stream in the half-plane y > 0 is initially different from that in y < 0 but each stream is of such a character that downstream of x = 0, where they are allowed to unite, they may together form a combustible mixture. We wish to examine the disturbances created by the mixing and burning process, with the overriding assumption that the entire flow field is laminar. In order to accomplish this in a unified way we shall adopt the Oseen approximation (which linearizes the convective terms in the conservative equations), and will therefore follow Lagerstrom, Cole & Trilling (I949) and Laurmann (I958, I96I). The first group of authors used this method to elucidate the behaviour of a compressible, viscous, non-heat-conducting fluid. Laurmann included the effects of heat conduction and considered slip flows past finite and infinite flat plates. We generalize the basic sets of equations used by these authors to include the effects of variable chemical composition and its consequences. Apart from the Oseen-type of treatment which is to be used here, other, similar but not identical, studies have been undertaken previously. Closest in character to the present work is that carried out by Lilian (I963), who has dealt with comparable configurations with the aid of laminar boundary layer theory. Much of Linian's effort is directed towards an attempt to explain ignition and extinction phenomena. This will not be our immediate concern; rather do we propose to analyse one special configuration in a fairly detailed way. It is worth pointing out too that Lilian's work is applicable to high Reynolds number situations whereas the present approach, aside from any benefits which it may bring in the way of a unified treatment of the field, is especially applicable at low Reynolds numbers. As will be seen, this may well be of some importance in any subsequent discussions of extinction phenomena.