CERES
https://dspace.lib.cranfield.ac.uk:443
The CERES digital repository system captures, stores, indexes, preserves, and distributes digital research material.2014-09-16T05:17:27ZAviation fuel problems at high altitudes and high aircraft speeds
https://dspace.lib.cranfield.ac.uk:443/handle/1826/8692
Title: Aviation fuel problems at high altitudes and high aircraft speeds
Authors: Goodger, E. M.
Abstract: Much useful data has appeared over recent years concerning the
problems incurred by continued increases in operational altitudes and
aircraft speeds. This report is an attempt to correlate a representative
amount of these data, and to present them in a form suitable both for
general information and for project design reference. Frequent references
are made to the literature as guides to additional information. Some of
the work has formed the basis of research activities at Cranfield.1959-01-01T00:00:00ZGoodger, E. M.An experimental investigation of the subsonic drag and pitching moment characteristics of slender cambered bodies with pointed noses and tails
https://dspace.lib.cranfield.ac.uk:443/handle/1826/8691
Title: An experimental investigation of the subsonic drag and pitching moment characteristics of slender cambered bodies with pointed noses and tails
Authors: Harris, K. D.
Abstract: It is known that supersonic aircraft are liable to possess some trim
drag under cruise conditions. Fuselage camber has been suggested as one
means of reducing this component of the drag, and the purpose of this
investigation was to obtain quantitative data on the pitching moment
increments obtainable from fuselage camber and incidence, and the associated
increments in fuselage drag.
Lift, drag and moment measurements have been made on a body representative
of the fuselage of a supersonic transport aeroplane. The fineness
ratio of the body was 15:1, the cross-sectional area distribution being
of modified Sears-Haack form. Parabolic nose and tail camber was used,
the nose and tail portions being made removable so that a variety of
different configurations could be tested. The Reynolds number of the
tests was 14.1 x 106 based on the length of the model, and the Mach number
was 0.2. The tests were made with a transition wire attached to the model
at 10% of the length from the nose. A preliminary investigation indicated
that the Reynolds number was probably sufficiently large to ensure that
the results would give a good guide to the full scale characteristics.
The experiments showed that nose camber produces a pitching moment
increment in very close agreement with the predictions of inviscid slender
body theory. The increments in lift and drag, whilst not zero as predicted
by inviscid theory, axe small. Tail camber on the other hand gives rise
to much larger lift and drag increments, and the increment in pitching
moment is quite different from that predicted by inviscid theory. In the
present tests the pitching moment increment due to tail camber amounted to
about 10% of the theoretical value.
The scope of the experiment was insufficient to answer the question
“What is the optimum fuselage shape for minimum trim drag?" However, the
indications are that an uncambered fuselage at incidence will provide a
given pitching moment for less drag than any cambered fuselage. This
however neglects the interference effects of the wing and tail unit on the
fuselage, and of the fuselage on the wing and tail unit. For reasons of
(i) tail clearance on take-off and landing, (ii) cockpit layout and view,
and (iii) cabin layout, fuselages with camber may be required. Some
indication of the fuselage drag penalties likely to be sustained by these
modifications of the fuselage are given by the results of this experiment.1958-08-31T23:00:00ZHarris, K. D.The flow of chemically reacting gas mixtures
https://dspace.lib.cranfield.ac.uk:443/handle/1826/8690
Title: The flow of chemically reacting gas mixtures
Authors: Clarke, J. F.
Abstract: Suitable forms of the equations for the flow of an inviscid, non-heat-
conducting gas in which chemical reactions are occurring are derived,
The effects of mass diffusion and non-equilibrium amongst the internal
modes of the molecules are neglected.
Special attention is given to the speeds of sound in such a gas
mixture and a general expression for the ratio of frozen to equilibrium
sound speeds is deduced. An example is given for the ideal dissociating
gas. The significance of the velocity defined by the ratio of the convective
derivatives of pressure and density is explained. It is the velocity
which exists at the throat of a convergent-divergent duct under maximum
mass flow conditions, and it is shown that this velocity depends on the
nozzle geometry as well as on the 'reservoir' conditions.
As an illustration the phenomena of sound absorption and dispersion are
discussed for the ideal dissociating gas. The results can be concisely
expressed in terms of the frozen and equilibrium sound speeds, the
frequency of the (harmonic) sound vibration and a characteristic time for
the rate of progress of the reaction.1958-11-01T00:00:00ZClarke, J. F.The exact flow behind a yawed conical shock
https://dspace.lib.cranfield.ac.uk:443/handle/1826/8689
Title: The exact flow behind a yawed conical shock
Authors: Radhakrishnan, G.
Abstract: The exact flow behind a yawed conical shock wave is investigated. A numerical method of solving the differential equations of motion behind the shock wave is evolved. This method is applied to the case of the flow of a perfect
gas behind a conical shock of semi-apex angle 30 degrees yawed at 20 degrees to a free stream of Mach number 10. The shape of the body which would produce such a shock wave is determined. The properties of the flow between the shock wave and the body surface are investigated particularly with respect to the
variation of entropy and the streamline pattern.
The existence of a singular generator on the body surface in
the plane of yaw and on the "leeward" side, at which the entropy is many-valued is brought out. It is found that, downstream of the shock, all stream lines curve round and tend to converge to this singular generator.
The body obtained by the present investigation is compared to
the yawed circular cone which according to Stone’s first order theory would produce the same shock wave dealt with in this particular case.1958-04-01T00:00:00ZRadhakrishnan, G.