Showing papers by "Vaughn College of Aeronautics and Technology published in 1963"

A Bouncing Liquid Stream

Abstract: I WISH to report an unexpected effect observed when a thin stream of a solution of polyisobutylene in ‘Decalin’ is poured into solution in an open dish.

Crack formation in blanking and piercing

Abstract: In recent experiments on blanking and piercing it was found that cracks occurred in the region of maximum hardness gradient and that cracking could be eliminated by radiusing the punch and die edges. In this paper a simple stress analysis is made of the corresponding plane strain deformation, account being taken of the strain-hardening property of the work material. The above experimental observations are then shown to be compatible with the predicted stress distributions.

Reaction of Phenyl Isocyanate with 2,3-Epoxy Propyl Phenyl Ether (Phenyl Glycidyl Ether)

Abstract: REACTION of phenyl isocyanate and 2,3-epoxy propyl phenyl ether gives a one-to-one addition compound, and there is evidence to suggest this is 3 phenyl 5 phenoxy methyl 2 oxazolidono. The reaction is believed to be: This is similar to a reaction reported by A. Thompson1 between acidulated potassium cyanate and epichlorhydrin. Evidence for the foregoing scheme is: (1) Reaction with alcoholic potash yielded a compound in agreement with the reaction: The product of this reaction gave a yellow oil on reaction with nitrous acid, suggesting a secondary amine. (2) There was no reaction of the reaction product with nitrous acid. The nitrogen of this compound is thus not present in the form of a primary or secondary amine. (3) The product of the reaction was broken down by heating with concentrated hydrochloric acid in a sealed tube at 200° C to give an oil, which was shown to be a chlorine containing compound. This is in agreement with the concept of acid hydrolysis of the oxazolidone ring.

The Part Played by Wind Tunnels in Modern Aeronautics

Abstract: The wind tunnel has been the main instrument for experimental research in aeronautics since the turn of the century and its history is as brief as powered flight itself. It has always played a leading rdle in aeronautics right from the time of the Wright Brothers to the present day. The early form of wind tunnels as developed at the National Physical Laboratory and other research establishments have been replaced over the years by larger and more elaborate facilities, each having a particular speed range and specific role in aeronautical research and development. Modern wind tunnels having continuous operation of the type installed at the Royal Aircraft Establishment involve powers of up to 100 000 h.p. and cost in the neighbourhood of £10 000 000. In spite of this cost it is a sobering thought that, if anything, the overall cost of each data point is less today than it was in the early days of aeronautics. Such tunnels are highly complex instruments for research and development and although they play a role similar in many respects to that of a computer, they have the advantage of always dealing with a real fluid. Indeed no known computer could cope with the range of problems that can be solved in a wind tunnel, ranging from such complex problems as the structure of turbulent flow to the pressures in separated flow regimes, to quote just two examples. This fact must always be kept in perspective when arguments are presented for more and more work on digital computers to solve basic fluid motion problems. Of course we cannot overlook the problems of interpretation of wind tunnel data and the difficulties encountered in extrapolating these data to flight conditions. The development of theories for such problems together with answers is of ever increasing importance, especially as the problems in aeronautics are becoming more and more complex. These solutions have the important function not only of high-lighting certain aspects of the flow, but of pin-pointing the important parameters in a problem together with providing better than order of magnitude results. However, theories must be based on physical facts and these can only be determined in the final analysis from experiments. The wind tunnel has three highly significant roles in modern aeronautics: (i) Experimental research as a forerunner to future theoretical research. (ii) Experimental research as a confirmation and extension of theory. (iii) Current research and development work on a given aircraft. The current trend in bringing strong theoretical and experimental groups together, plus the employment of rapid measurement techniques in wind tunnels, promises the greatest possible productive utilisation of these highly important and expensive facilities. In most cases today they are playing a strong, if not the leading, role in aeronautical development.

Comment on a Conjecture of Tanner

Abstract: where a / and / ? / are (x / 26A) [/t + V^ 2 —1] / 2 respectively. Substituting for / (y) and g (x) in equation (8) gives w2 (x, y). The deflection surface w (x, y)=w1 (x, y) + w2' (x, y) is therefore given by xg 1 a [cosh a'y cosh jS'y\"] *' W = w i <*' y> + 1277 j ( a ' ) 2 ( ^ T [cosh or7> ~ cosh £'Z>J' xx b [cosh a,'x cosh/3,'*l i:yl cos ^ + 7 ^ ^ ^ , I =zr±-. ~ = ^ \\ « * 5 J ' 2a \"*\" ( a / ) 2 (/S/) [cosh a,'a cosh /?, (12)

Paper 1: A Review of Analytical Studies of Reacting or Relaxing Gas Flows

Abstract: The status of the analytical, as opposed to the purely numerical, approach to problems of reacting or relaxing gas flows is examined by way of a summary of the significant results which have been achieved by this means to date. Much of the work deals (inevitably) with a review of the linear theory, although more exact treatments of nozzle flows, shock wave structure, characteristics and first-order wave theories are also dealt with.Finally an attempt is made to assess the limitations and probable lines of development of the analytical study of real gas flows.

A creep model

Abstract: The introduction of recovery into the logarithmic (exhaustion) creep model leads to a form of creep curve which accords with the experimental observations. In particular, an approximately cubic transient creep, followed by a steady state creep, are both exhibited. The general properties of the model require more detailed investigation, but the initial results at least demonstrate that a distinction between the rate-controlling processes in the transient and steady state regions is unnecessary.