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A summary of the scale model wind tunnel tests on the TRRL spray dispersion articulated tanker vehicle
No full textAn investigation into the machining of titanium 150A in the Forged State
No full textTests to investigate various aspects of machining have been
carried out at The College of Aeronautics on a billet of Titanium - 150A,hot forged by High Duty Alloys. Measurements were made of the drilling forces, and an investigation of the cutting force when turning the blank was made. Tests were also made to determine the effect on tool life of tool shape, cutting speeds, of various rates of feed and of cutting lubricants and coolants
Addendum to a theoretical and experimental study of the boundary layer flow on a 45 degrees swept back wing
No full textCOA report 109 describes Flight Tests carried out on a swept back half wing of double elliptical section to investigate the nature of the boundary layer flow, with particular reference to Bounday Layer Instability and subsequent transition.M.O.S. contract No. 6/ Aircraft/14002/C.B.6 (a
Independence of helicopter rotor derivatives under non-uniformity of induced velocity distribution at low forward speed
No full textA radial parabolic induced velocity distribution agreeing closely with flight measurements has been used for the hovering case. Continues..
The effect of density on jet flow at subsonic speeds
No full textOn the assumption that the velocity and density distributions
across a jet of one gas issuing into a stream of a second gas are of
exponential form, the momentum integral approach has been employed to
find the variation of centre-line velocity downstream of the potential
core. The results for the particular case of a jet issuing into a gas
at rest are equivalent to those found theoretically by Blottner (Ref. 2)
and experimentally by Keagy and Weller (Ref. 1). The results for the
jet issuing into a moving stream agree with the limited experiments of
the present author.
These calculations show the importance of jet to free-stream density
ratio with respect to the rate of decay of the jet downstream of the
mixing region
On the sudden contact between a hot gas and a cold solid
No full textThe flow induced by the sudden contact between a semi-infinite
expanse of gas and a solid, initially at different temperatures, is
examined on the basis of a linear continuum theory. For times large
compared with the mean time between molecular collisions in the gas,
the velocity and pressure disturbances are found to be concentrated
around a wave front propagating out from the interface at the ambient
isentropic sound speed, whilst, near to the interface, these disturbances
are small and the gas temperatures are nearly equal to those predicted
by the classical constant pressure heat conduction theory.
The possible significance of these results in connection with
reflected shock wave techniques to measure high temperature gas
properties is commented upon
On a problem involving heat conduction through a polyatomic gas
No full textA heat conduction problem is set up which, in essence, simulates the conditions
arising when a plane shock wave reflects from a co-planar solid boundary. The gas
is assumed to be polyatomic, with one 'significantly relaxing' internal energy mode.
The quantity of primary interest is the temperature of the solid at the interface,
since this can be observed experimentally without much difficulty. Solutions are
obtained for this quantity which cover a range of practically plausible relaxation times
and 'wall effect' parameters. It is essential to include proper temperature jump
boundary conditions for both active and relaxing (or inert) energy modes. Thus it is
necessary to know accommodation coefficients for these modes of energy storage.
The temperature jump effects are found to dominate the (interface) solid's temperature/
time history, with relaxation effects playing a very secondary role.
The theoretical results are compared with some experimental observations and
encouraging agreement is found. As a result of this agreement it proves possible to
estimate the accommodation coefficient for the active modes (in this case for the
combination platinum/air), the pressure being about 15 atmospheres. The pressure
sensitivity of accommodation effects is commented on
The elastic stability of sandwich plates
No full textThis paper treats the elastic stability of supported
rectangular plates of sandwich construction with isotropic and
aeolotropic fillings under compression and shear loading.
Formulae are developed for critical stresses for flat and
curved panels in compression and flat panels in shear for the
buckling of the whole panel, also for the wrinkling or local
failure of the faces of flat panels in compression. A method
is indicated for calculating the critical load of a cylinder
in pure bending.
It is established that for a wide range of conditions
the critical stress for panels buckling in compression is
independent of the form of the filling providing it is
symmetrical about the normal; of the elastic constants of
the filling only the transverse shear is of concern. As a
result a simple extension of the equivalent plate theory of
greatly improved accuracy is developed enabling the use of
equations treating the plate as a whole
Addendum to type record. Avro "Lancaster" Mk.1 P. A. 474 Type record No. 1/P1/Lancaster. Investigation of boundary layer conditions on wings. M.O.S. Contract No.6/Aircraft/9807/C. B. 6(a)
No full textIntroduction
The investigation involves, briefly, the mounting of a wing
of 45' sweep-back in a dorsal position on the fuselage of
'Lancaster' P.A.474 such that wing incidence will be variable
in flight over a 20 range, i.e. ± 100.
A ‘partial chord’ technique for swept wings has been
established by the College using a similar wing mounting
configuration on an Avro 'Anson' Aircraft and this technique has
been applied to the current investigation