https://reports.aerade.cranfield.ac.uk/handle/1826.2/4114 Wed, 11 Mar 2026 20:02:47 GMT 2026-03-11T20:02:47Z https://reports.aerade.cranfield.ac.uk/handle/1826.2/4872 The influence of flow parameters on minimum ignition energy and quenching distance Experiments have been carried out on the effects of pressure, velocity, mixture strength, turbulence intensity and turbulence scale on minimum ignition energy and quenching distance. Tests were conducted at room temperature in a specially designed closedcircuit tunnel in which a fan was used to drive propane/air mixtures at subatmospheric pressures through a 9 cm square working section at velocities up to 50 m/s. Perforated plates located at the upstream end of the working section provided near-isotropic turbulence in the ignition zone ranging from 1 to 22 percent in intensity, with values of turbulence scale up to 0.8 cm. Ignition was effected using capacitance sparks whose energy and duration could be varied independently. https://reports.aerade.cranfield.ac.uk/handle/1826.2/4872 https://reports.aerade.cranfield.ac.uk/handle/1826.2/4868 Aeroplane design study STOL airliner (A71). Part 3- low speed lift and control The potential application of advanced forms of aircraft control to civil operation appears to be capable of being split into two areas. First, those aircraft which are very large, whose rotary inertia tends to reduce the effectiveness of conventional controls. Second, those aircraft whose specification dictates that the aeroplane be flown at very low speed. Again conventional controls become inefficient due to decreased aerodynamic efficiency. The second category of aircraft has been considered in the form of an STOL aircraft. The control problems of an STOL aircraft with a 2000 ft runway capability (Ref.10) have been examined. It has been found that the aircraft is unstable and could require autostabilisation. None of the conventional controls were satisfactory and each required augmentation. The single strip crosswind requirement penalises the design most heavily since this requires over half of the extra control power necessary. The total augmentation for blowing air amounts to an equivalent thrust of approximately 6700 lb. This is equivalent to 11.5 per cent of the total installed aircraft thrust. https://reports.aerade.cranfield.ac.uk/handle/1826.2/4868 https://reports.aerade.cranfield.ac.uk/handle/1826.2/4867 A preliminary study of survival rates in civil aircraft accidents, 1966 - 1973, with particular reference to fire risk and fuel type To establish whether theoretical and laboratory safety advantages of low volatily fuel, such as that of low rate of flame spread, are reflected in aircraft accident 'statistics' a preliminary study has been made of the ARB's world airline accident summary. An advantage has been found in that the change to kerosine has apparently halved the death rate in survivable accidents. In all gas turbine accidents, including those where death was probably due to impact not fire, the death rate seems to be 50% higher with wide cut gasoline than with kerosine. It has also been found that a higher proportion of gasoline powered aircraft accidents involved impact death 1.1-1d that overall the survival rate has remained virtually unchanged. A critical examination of these preliminary findings, in the light of the relevant accident reports, is planned. https://reports.aerade.cranfield.ac.uk/handle/1826.2/4867 https://reports.aerade.cranfield.ac.uk/handle/1826.2/4863 Report of the project design of the Cranfield A-90 short haul 500-seat airliner project This report describes the conceptual and detail design of the A-90 Short-haul 500 seat airliner project. It started with a market investigation which then lead to the specification of the aircraft. The author performed a conceptual design process, to derive the configuration - a twin-engine jet transport with a swept wing, shoulder mounted to a large double-bubble fuselage. Aerodynamic, mass and geometric work was then performed prior to the start of the main design programme in October 1990. The main programme involved 23 MSc students and 5 members of staff and lasted for 8 months. Each student was given responsibility for the detail design of a major component such as outer wing, fuel system, etc. This work is described together with the final design that emerged. This description is aided by the reproduction of numerous engineering drawings. The work was complemented by extra studies, performed by 15 Flight Dynamics students. The report then discusses the final configuration of the A-90. The project showed the potential of meeting mass, cost and airport requirements. It should exceed the range requirements and carry 620 passengers for 1700 n miles, 500 for 2260 n miles or 345 for 3500 n miles. The design showed considerable flexibility and could be relatively easily developed to carry some 1000 passengers. Investigations were performed of several applications of new technology, including variable camber flaps, fibre optic flight controls, "all electric" systems and modern materials. They all looked feasible, and should be investigated further. The main concern was the provision of bleed air and secondary power following the loss of one engine, on such a large aircraft. Careful system design overcame this problem. The A-90 project proved again the validity of Cranfield's group design project as a powerful means of educating design students. https://reports.aerade.cranfield.ac.uk/handle/1826.2/4863