Meals pinch the limelight
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Istitute of Fuel/Institute of Sound and Vibration Research ymposium reported by Paul Brockington
Promising results in application of insultation to a combustion chamber Two-stroke turbocharged diesel with favourable fuel consumption at lower loads Condemnation of costly measures to obtain impossibly low pollution levels
E BELIEVE in the sel," said Dr T. Priede, .d of the ISVR. Autotive Group, in the openaddress of the final dission at the loF/ ISVR aposium held at the iversity of Southampton Wednesday of last week.
d later he outlined a kject of the ISVR which, claimed, demonstrated one way in which major igress could be made in sel development.
rhe diesel, he said, had fly advantages over other ms of power unit, includ, efficiency and long life, was a valuable asset in -1 conservation. Its main advantages; more noise weight.
Thrrently, 30 per cent of : energy input of convennal diesels was wasted by it loss in the coolant, and lucing this loss was the ly means by which a big provement in diesel aracteristics could be tamed.
Related work at the Instite included insulation of 2 combustion chamber d promising results so far d included a reduction in at-loss-to-coolant to 10 r cent together with a gulator saving in fan iwer and noise.
Dr Priede mentioned the ed to reduce the weight as 11 as the noise of diesels d to improve combustion ficiency. In a later mment another speaker's ntribution to the discusm, he said he could not as t envisage any alternative the diesel engine for rries or to the petrol engine r cars. Performance curves of various types of diesel engine relating to the paper on turbocharging by Dr D. Anderton and Mr V. K. Duggal of the ISVR showed that a 9.3-litre turbocharged two-stroke .(obviously a General Motors unit) had a big fuel consumption advantage over the others when running at its rated speed and developing less than 58 per cent of its maximum bmep. It had a similar advantage at its intermediate speed rating plus near compatibility with the best at higher bmeps, the best in both cases being an 8.2-litre diesel with a matched turbocharger.
A delegate from a company producing fourstroke diesels told CM that the two-stroke could benefit to a greater extent by the application of matched turbocharging, and he also said that "everyone" was interested in the potential of sound-deadened steel produced by the British Steel Corporation. This is a laminate with a plastics interlayer.
Pilot injection
Will there be a revival of interest in pilot injection? Mr A. Wilson, chairman of The Institute of Fuel (South Coast section) mentioned the experimental application of twin injectors, with which he was associated in 1945 and which had converted a noisy air-cooled engine into a smooth running quiet unit, and he suggested that this indicated the potential of pilot injection. Another speaker pointed out that the injection of very small quantities of fuel, which was essential to pilot injection, was difficult to control and involved a fuel consumption penalty. The system could, however, reduce the non-mechanical noise level of a diesel by 50 per cent and further developtnent work could be worthwhile. It might be employed in place of a turbocharger to reduce noise.
In a lively presentation of a paper on road transport in the future, Prof P. D. Dunn, of the University of Reading, mentioned the use of a fluidized bed in applications of the Stirling engine. (A fluidized bed enables heat to be produced by rapid oxidation as distinct from combustion.) In a comment on hybrid systems, he said that the possibility of developing an efficient Stirling! electric vehicle should be taken seriously.
On the same subject, Mr P. Draper, of the National Society for Clean Air and of The institute of Fuel, said that the best type could comprise a very small gas turbine which operated on/off to charge the battery of an electric drive system.
Pollution waste
Hundreds of thousands of man hours were being wasted to obtain impossible pollution levels, according to Mr Draper, and this view was symptomatic, in general, of the mood of the delegates. Why do it? He asked. It was political;' it should be adapted to the requirements of practical people. To wasted effort and fuel could be added higher maintenance costs.
Later, Mr Draper said that the possibility of reducing a pollutant was not in itself a good reason for spending large sums on doing it. Of more immediate interest, he maintained that the smoke level of small diesels was too high; they should be derated.
Commenting on these viewpoints, Mr F. E. Ireland, president of the IoF and a member of the DoE, referred to the frequent changes of pollution regulations in America. In the USA, he said, there was no inducement to fix standards at a level below that which makers could achieve. In the UK there was a get-together of all concerned with the problems to determine standards.
In a -favourable reference to the paper on urban planning and road transport, presented by Mr A. J. Wilson, of Hampshire County Council, Mr Ireland said there was a connection between planning and pollution which involved a philosophical element. The. Government should make up its mind and come out with a guidance policy. The example of the Japanese was relevant; they got on with the job of decision making applicable .to large numbers of people.
Elaborating on certain aspects of his paper, Mr Wilson said that a reasonable assessment of North Sea oil resources, based on projected UK consumption, gave promise of self-sufficiency over a very limited period of 15 years from 1980 to 1995. It would be a mistake to regard North Sea oil as a future means of eliminating the need for oil imports.
Improved transmissions
Author of a paper on gas turbines for road transport, Dr M. G. Hodskinson of British Leyland truck and bus division claimed that improved transmissions could reduce fuel consumptions very substantially by providing for operation for lengthy periods at around mid-speed and 75 per cent of maximum torque. In the case of a petrol engine a saving in specific fuel consumption by as much as 40 per cent might be achieved. "We could do a great deal with transmissions", he said, The Americans had been doing the wrong things.
Tribute was paid by a number of speakers to Dr Hodskinson's paper with particular reference to the information he gave regarding the potential competitiveness of the gas turbine with the petrol engine. More than one speaker, however, expressed surprise that the turbine could possibly compete with the, petrol engine.
Winding up the symposium, Mr Ir stated a view which evic typified the opinion c majority of the delegan said that in the recent anti-pollution measure taken precedent over formance. The energy had changed the ord importance and per] ance now came firs pollution standard shot evolved for the UK so t form of legislation wou available when require consideration by the E