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Ministering to special needs

23rd February 1980
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Page 40, 23rd February 1980 — Ministering to special needs
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Which of the following most accurately describes the problem?

Graham Montgornerie v,sits -wo consultant organisatons in e Soun one concernec with building up power, the o-ler wi ensuring tnot if doesnf get out of hand

I THE AUTOMOTIVE world,

all research work is carried it in the inner sanctum of a ctory's research and developent department. Much of the Drk is done at outside estabhments specialising in par:ular areas and acting as insultants to the manufacrer.

The South of England is the 1:ation for two such organisains, Ricardo at Shoreham-by)a and the Institute of Sound id Vibration Research at mthampton University.

Both organisations have ade a significant contribution car design as well as comercial vehicles.

Ricardo Consulting Enginrs Ltd was formed over 60 ars ago by Sir Harry Ricardo Shoreham-by-Sea in Sussex r the purposes of research into e internal combustion engine. Today, the company — still at ioreham — employs over 300 !ople in activities ranging from search and design to inrumentation and computer The company is retained by any clients (over 110 in fact)

a consulting and general chnical assistance basis. though some companies iproach Ricardo with a specific oblem, it is very easy to get to spinoff areas when it bemes difficult to decide where e original job begins and ends. Thus Ricardo prefers to have overall consulting agreement ah the client which, in the ards of David Collins, Ricar)'s client services manager, ves an -umbrella coverage-. is means that the client can en pose questions not necesrily related to the original proem.

Ricardo is not retained just by companies. At the moment ore than half of the clients are )m countries as far apart as the SA, Scandinavia, South Korea and Yugoslavia.

Two notable achievements in recent months have been a second contract from China for work on a diesel engine for use in an agricultural tractor and one from the Czech manufacturer Tatra for work on their highly rated air-cooled diesel power units.

One interesting area of expansion for Ricardo activities has been in providing design expertise. to companies where a motor industry had consisted of building under licence.

Once such companies are established, then it is logical that they should want to develop their own engines to suit their own specific market needs more exactly.

With an engine, the actual design stage represents only a small proportion of the total cost, The major costs came from prototype building, testing and finally production tooling.

Once a company is into engine building via a licensing agreement, then it is comparatively easy to progress to its own design. Or as David Collins put it "it's like starting with a clean sheet of paper but with half the lines drawn for you".

Ricardo also gets involved in

true -clean sheet of paper" design work where a client will give a requirement for an engine covering the range x to y horsepower and asking Ricardo for recommendations.

A conceptual design study will then be carried out to sort out such basic parameters as whether the engine is to be turbocharged or naturally aspirated. Is it to be common cylinder size for modular assembly? Is it for lorry or passenger car application and so on.

This is the stage which Ricardo thinks is the most important. it has happened that a manufacturer has had fixed ideas on a certain point and refused to budge, which has led to the inevitable compromise. For this reason Ricardo likes to work in very close collaboration with the client from an early stage.

Although close collaboration is essential, this does not mean that the client's representatives become resident at Shoreham for a time. Because of the very nature of Ricardo's business this poses too many problems of confidentiality.

The company has to carry out research work of its own as well to stay in the forefront of automotive technology. This is funded partly out of clients'. fees — in fact about ten per cent of the Ricardo turnover is spent on pure research.

One area of Ricardo involvement concerns alternative power units, with the company being very active on development of the Stirling engine as a result of being a sub-contractor to United Stirling of Sweden, who in turn are involved in a development programme funded by the Department of Energy in the USA.

Most of the Ricardo work has been concentrated on the mechanical side of Stirling research rather than combustion. The current design is in square four configuration with two rows of two cylinders side by side and the two crankshafts linked together.

Although UK interest in the gas turbine for automotive purposes has faded over the last couple of years, Ricardo still maintains an interest. One of the 'easons for the company's continued involvement is because Df the materials development spinoff.

For example, Ricardo has run :urbines made from ceramic -naterials at high speeds and -Ugh temperatures and achieved he design requirements which were 100,000rpm at a temperature of 1000° K (727('C or 1340F).

Although Ricardo is still workng on the gas turbine concept, he company does not envisage :he passenger car of the future Doing so powered. Rather, it is n the 350 plus horsepower field that Ricardo sees the turbine's possible future.

The steam engine operating on the Rankine cycle received an investment boost about ten years ago because of its good emission characteristics.

However, it does not give good fuel economy although it can accept a wide range of fuels. Ricardo is not involved in any steam engine work at the moment but it is monitoring events in the rest of the world.

Basically, Ricardo is in the engine business from the smallest to the largest, embracing all types of combustion systems. The company is not in the vehicle field as such, although it is now moving into the transmission side because of the importance of drive line matching and its effect on en

gine economy. This is one of the main areas where economy progress can be made, according to Ricardo.

As far as the continuously variable transmission is concerned, Ricardo is not particularly enthusiastic about the state of the art as it stands at the moment. As David Collins put it: -all the examples we have seen so far have not had the efficiency of a mechanical transmission''.

On the passenger car front, Ricardo sees future trends for lower engine speed — a path already being followed by the diesel market, of course. Future vehicle gearing might rise as high as 30mph per 1000rpm which would mean that the engine was operating over a smaller speed range.

Thus a multi-step (by passenger car standards) gearbox would be required which would feature a microprocessor-controlled mechanical shift as part of a total engine management system. The microprocessor would decide on the right combination of variables.

In the early days of the company under Sir Harry, much of Ricardo's work was on alternative fuels — mainly of the alcohol based variety. This was because the quality of petrol in the 1920s was the limiting factor on engine performance and so alcohol was used to get a higher anti-knock rating.

The interest in alternative fuels disappeared completely when the lead compound additives were developed to eliminate the anti-knock problem, but interest is now being renewed because of contemporary energy problems, Ricardo considers an alcohol/dery mix to be unappl cable to the diesel engine. Th spark-ignited alcohol line, how ever, is currently being followei by several manufacturers, witl Volkswagen and Fiat offerini cars for the Brazilian marke which run on 100 per con alcohol.

Ricardo thinks that ai "alternative fuel" should be hydrocarbon from a non-oi source. This is considered al important point as, for example the US Department of Energ: considers a wider cut of al existing oil-based fuel to be al "alternative fuel".

The company is very active ii

emissions research, havinl been involved with both petrc and diesel work from the ver beginning. When the environ mentalist's spotlight turned or to emissions a few years ago Ricardo got a lot of custom be cause of the company's exper tise and proven test facilities.

This is where research worl

funded by Ricardo for Ricardo essential. As I mentioned ear lier, some of the work done a Shoreham is pure research, car ried out to build up the corn pany's "memory bank" of e), perience and information whict can then be drawn upon by tht various clients throughout tht world. As David Collins put it "'we always try to keep one stet ahead of the game-. This particularly applicable when legislation is involved.

Ricardo's emission worl really began around the mid Sixties on petrol engines — par ticularly two-stroke units. All thi early work, in fact, was on petro engines as the early emissior regulations did not apply tc diesel power units.

Now there is a great deal o iterest in diesel-powered cars iroughout the world because of leir proven economy. Because f the road speed requirement, le high revving capability of an ldirect injection diesel engine i necessary for car use.

Ricardo has put in a lot of 'ark on direct injection engines )• get them to operate over a imilar speed range to the idi Init. Although an economy ■ enefit was measured on the ast bench, this has not so far leen repeated on the road as the .ngine had to work harder beause of the limited speed ange.

In Ricardo's opinion, the idi ingine will never achieve the iconomy of the di equivalent iecause of the pumping losses icross the throat of the iharnber. Currently the fuel iconomy of a di engine is iround ten per cent better than in equivalent engine fitted with in indirect injection combustion iystem.

lest rigs Much of Ricardo's combusion research work is carried out )n single cylinder engines and he company has actually deiignecl and produced its own .ange of single cylinder engines Or research purposes.

The largest of these is a diesel init code-named Atlas which las bore and stroke dimensions )f 216x241mm (81/2 x91/2in) or operation at ratings up to 3800kH /sqm (550psi) mean Wective pressure.

For the heavy duty highly -ated automotive application, Ricardo has the Proteus which :avers a bore size range of 100 :o 150mm (3.9 to 5.9in). At the ower end of the scale comes the Hydra which can be operated as 3 petrol or a diesel powered unit over a bore range up to 105mrn

Ricardo has used single cylinder engines in conjunction with a Laser Doppler Velocimeter (LDV) to find out just what is happening to the air swirl in the inlet port.

The company decided to embark on a major research programme in this area, as it felt that more information was needed to identify the main features of the air flow pattern.

There are over 70 test beds at the Shoreham site, all involved in practically every aspect of ic engine development. This also includes work for the motor cycle manufacturers — mostly on the emissions side.

Total design

If Ricardo is called in by a client at the design phase of a major project, the work is usually divided into stages: • conceptual design covering the evaluation of the main features • main design — where the specifications of the major components are decided • detail design — including producing working drawings from which prototypes can be With the building of prototype engines in mind, Ricardo has a fully equipped workshop which can produce a batch of prototype engines of perhaps 30 in number.

The Institute of Sound and Vibration Research at Southampton University consists of a number of groups: fluid dynamics and acoustics, operational acoustics and audiology, structural dynamics, automotive engineering, data analysis, electronic research and the industrial noise research and development group.

The automotive group has been involved in a number of projects including the much publicised Quiet Heavy Vehicle. This was the result of a joint effort sponsored by the Transport and Road Research Laboratory involving ISVR, Fodens, Rolls-Royce, MIRA and the National Engineering Laboratory.

The object behind the exercise was to reduce the overall external noise from the vehicle by attention to the individual noise from the engine, exhaust, fan and tyres.

ISVR did much of the basic ground work to establish a datum noise level. This was done by installing the 350 horsepower Eagle engine complete with gearbox in an anechoic test cell at Southampton with the dynamometer situated outside the cell so that its noise did not confuse the issue.

For similar reasons the air intake was mounted outside the test cell and the exhaust downpipe was lagged. To assess the relative importance of different parts of the engine, the whole power unit was covered with lead sheet lined with glass fibre matting.

Each component was then uncovered in turn and the noise level measured. Although this is not an accurate method of measuring the individual noise output, ISVR claims that it does put the various areas in order of priority as far as sound radiation is concerned.

The ISVR studies found the order of importance to be (a) structure; (b) sump; (e) fron end; (d) gearbox; and (e) inlet The ISVR suggestions made ai appreciable difference to th, basic structure of the researcl engine as the timing gears wer, moved from the front of the en gine to the rear, and the botton deck of the cylinder block wa moved down to the lower end c the cylinders to form a rigii section at that point.

The project was a corn plot' success, with the final nois, level being nearly half that of th, standard engine. The total QH project was also a success witl the resultant internal and extei nal noise levels being equivalen to a Morris Marina.

Thus the work at ISVR is no just of the pure research -ivor tower" variety but has a valio place in the future developrnen of the commercial vehicle.

Finite element technique have been used for some time a Southampton, with one mock in particular being developed tj predict the vibration modes an natural frequencies of shee metal car and light van bod structures.

Like Ricardo, ISVR us single-cylinder engines fo much of their research work Current work in this field in cludes a study of the problem involved in using a direct injec tion diesel engine for private ca application, The turbocharger has had , tremendous effect on all aspect of diesel engine performance uding noise. ISVR has done ch work on the effect of the Docharger on engine corntion noise, culminating in a ailed study of the result of ying the turbocharger metry.

his work has shown that the metry is a controlling fea

according to ISVR. Further .k along these lines will in1e running at very high igs near the limit of turborger capacity.

n the passenger car field, thampton has carried out ie initial running tests on the DC funded lightweight diesel ine, of which the main cont is that the crankcase walls lot connected directly to the n journal supports which are :ilevered from the stiff lower nder deck, thus enabling tweight materials with a low iral frequency to be used for he Institute is very icious of the popular opinion university research bears little or no resemblance to the real needs of industry. This is one of the reasons why the university is experimenting with four-year degree courses, including periods of industrial experience.

In such a course, a student would cover all the material of a typical three-year course but the final part would be directed More to engineering design, production and construction methods and engineering management.

ISVR is certainly capable of applying systematic research to arrive at a finished product. The 0.1-IV project proves that. Regrettably, however, it is not possible here to go into specifics about any other contract work for industry because of confidentiality, another feature shared with Ricardo.

This is a great pity as there are some fascinating projects currently being pursued at both Shoreham and Southampton


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