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The still was taken from a video I have that has old Chrysler films on it.
Remarks by George J. Huebner, Jr., Director of Research, Chrysler Corporation, at a meeting in Detroit with representatives of the press, radio and television on Tuesday, April 12, 1966.
(This is one of three documents sent to my father by John F. Bunnell (not the TV Sherriff) of the Chrysler marketing staff because of our interest and participation in the turbine car program. The program was over at this point and the results were in. Mr. Huebner was considered the father of Chrysler's turbine cars.)
We in Detroit's automobile industry may feel that the automobile is the most important sociological and economic factor in our lives today. But, since the automobile is also a business for us, we are accustomed to appraising it from quite an objective standpoint. So, when we find that people in the other parts of the country magnify our enthusiasm for something new, we are sometimes surprised. The story of the Chrysler automotive gas turbine embodied in our consumer-evaluation 50-car program has been, to may industry people, one of those sunrises.
The vehicle itself did not represent a drastic departure from the normal configuration of an American automobile. It is small, luxury car, equipped with power steering, power brakes, power windows and other customer conveniences. Standard instruments were to be found on the panel, with the addition of engine speed and temperature indicators.
Most of you here today are very well aware of the Chrysler Turbine research and development work which brought us to the 50-car consumer evaluation program. So, I will confine my remarks only to what we learned during this two-year period.
The turbine engine for the 50 cars was not considered to be a final production design. Most of the manufacturing techniques used for this limited quantity were necessarily those of the tool room and not the production plant. In many cases, this required a different approach to the design of the parts than would be used for engines produced in larger quantity by highly automated engine plants of today. But in it's basic concept, we felt that the power plant in the 50 cars appeared to have the potentiality of becoming an engine which could be manufactured in mass production volume.
During the course of the program, we had our first opportunity to observe and to judge the behavior of turbine engines under actual customer driving conditions. Thousands of hours of engine testing in laboratory test cells and many tens of thousands of miles of driving at our proving grounds and on the highways had not only given us the basis for rapid and continuous power plant development but had also proved reliability and endurance. However, the best "controlled testing" in the world cannot completely replace the great experience accumulated through the usage and conditions of daily operation when the vehicle becomes an everyday tool of transportation. For over two years our turbine cars were driven in cities and on highways, in deserts and in the mountains as well as below sea level.
The wealth of information derived form this experiment is invaluable. Of principal interest to us were the life of parts and components of the 50-car engines, their performance, their reliability, the degree and nature of maintenance required, the amount of training desirable for service people and the opportunity to test even more advanced turbine engine concepts by unexpected methods of operation also were revealed, indicating once again the value of use by non-experts.
Basically, all factors related to component life have been gratifying. We have had failures and disappointments, of course, but nothing we could even remotely consider unexplainable. The data available so far permit us to state that most parts have an endurance potential of over 50,000 miles. That is, as they were in the 50 cars, before the improvements the program has taught us we could make. Furthermore, although only one car achieved 50,000 miles in the two-year test, our inspections of high millage cars indicate that most of those pards will enjoy far longer life than 50,000 miles and pass the 100,000-mile mark generally considered acceptable for passenger cars.
However, there were a few parts that gave us "fits" because we could not readily duplicate field deterioration in the laboratory and consequently could not immediately pinpoint and solve the problem.
Regular inspections indicated that some engines had been subjected to temperatures very much higher than those normally allowed by the fuel control. Yet, a check of that component revealed no deficiency. It was finally notice, however, that some drivers would initial the automatic starting cycle with the ignition key and then very quickly shift the gear selector from start position before the engine had reached idle speed, thus by-passing the automatic start system. In a piston engine this is roughly analogous to over-choking resulting in scuffed pistons, piston rings, and cylinder bores. In a turbine the process is different, but the damage is still there, and we end up with scored regenerators and burned turbine blades. Once discovered, the trouble was an easy matter to cure, simply by modifying the automatic start system so that the driver could not over-ride and thus misuse it.
The most serious problems concerned the electrical system. Our use of a combined function starter-generator caused a severe operational deficiency. Although high altitude performance testing to 13,000 feet had been carried out in the mountains near Denver, Colorado, it was not initially discovered that a combination of high altitude and low humidity caused rapid and catastrophic destruction of the starter-generator brushes on the otherwise excellent unit. Subsequent investigation indicated that the addition of barium salts to the graphite brush compound would reduce or eliminate the high altitude brush wear, but with this change a fundamental problem remained. Under cold starting conditions the brushes were required to carry high current, thus requiring a soft, low electrical resistance short millage brush, whereas under generating conditions at commutator rotational speeds up to 20,000 rpm, a hard long-wearing brush with high resistance, was desirable. These mutually exclusive requirements were finally compromised in a brush which, under test, showed a life expectancy under 25,000 miles -- not considered satisfactory. This problem was corrected during the program but convinced us that automotive turbines should be equipped with separate starters and separate alternators.
Early ignitors showed distress at the thirty-day inspection period required for all of the cars. This distress was indicated both by the appearance of rapid electrical erosion and by severe oxidation of the electrodes, despite the fact that the electrodes are supplied with cooling air discharged as excess from the fuel nozzle air pump. Since the ignitor must be inserted through the combustor sleeve in such a way that it is continuously exposed to some flame impingement and to radiation form the hottest part of the flame, modifications to the hollow electrodes and the means of discharge or the cooling air from them were incorporated. Test millage on ignitors is now in excess of 20,000 miles. Although this may be satisfactory for a piston engine, it is not considered satisfactory for an automotive turbine and redesigned ignitors now under test will hopefully more than double this life.
On the plus side of the 50-car program has been the overall performance of the experimental turbine engine. Fuel millage on the 50-car test, although reasonable, was not quite as good as that of a comparable piston powered car. However, consideration must be given to the mode of operation which for most users included an abnormal number of starts and a high proportion of stop and go driving while demonstrating the car to interested and curious people. We believe that our own tests of fuel millage, which indicate fuel consumption comparable to piston powered cars, are more realistic.
Cold starting ability, claimed to be one of the greatest qualities of the turbine, proved to be just that. And of course, everyone appreciated getting instant heat in the passenger compartment on a cold winter day, or not having to think of anti-freeze. Power output of each individual engine as built remained consistently close to its original value, and even normal deterioration of power with usage ceased to bother us after the discovery of a highly efficient engine cleaner. In a piston engine, deterioration is corrected by a tune-up which, although not especially difficult, is costly and time consuming. In our turbine the lost power is recovered almost instantly by using a harmless compound which is simply introduced into the engine intake. It then removes accumulated deposits while on its way to the exhaust.
Chrysler Research was successful in developing families of low cost, low alloy content materials which are highly satisfactory for the purposes intended. A six percent aluminum-iron alloy, which we refer to as CRM-4 (Chrysler Research Material - Number 4), was used for much of the internal sheet metal in the engine. The strength required of most of these parts is not severe, and the hot strength of CRM-4 makes it a satisfactory low cost substitute for the far more expensive CrNi stainless steels used in aircraft.
The most critical phase of the research program has been the development of both materials and fabrication techniques for turbine wheels and nozzles. The compressor turbine wheel is subjected to a metal temperature or 1500 degrees F under full power. Although in passenger car applications this temperature is maintained for less that 10 per cent of the total operating life of the engine, this nevertheless represents a great number of hours and is further aggravated by the acceleration temperatures of the engine, which under some conditions exceeds the full power gas temperature of 1700 degrees F by as much as 135 degrees. This problem was solved in the compressor turbine wheels in the 50 cars by employing cast, CRM6D, a member of the family of high strength, high temperature, low cost turbine wheel alloys developed by Chrysler Research. The patent granted for this alloy shows that the material is principally iron and that alloying elements used are readily available domestically.
All but three of the engines in the 50-car program were operated with compressor turbine wheels integrally cast from CRM6D, and operating experience with this material has been highly satisfactory. The other three turbine wheels were made from an expensive, aircraft type, high temperature alloy. They were of the same general design and the Chrysler alloy wheels and although they did not fail, their operation was not completely satisfactory in this design because they caused other engine problems which were not present with the Chrysler material. In addition to these materials tests the opportunity was taken to test progressive design modifications and to explore various turbine wheel fabrication techniques.
A new and different, but still low cost, version of CRM-6D has proved satisfactory for the first-stage nozzle, which is subjected to metal temperature in excess of 1800 degrees F under acceleration conditions, and a further modification of 6D has been proved successful for the variable nozzle vanes.
An extremely beneficial aspect of the program has been the experience gained in turbine engine maintenance and in the training of service personnel. The five field service men and two supervisors kept close track of the days during which the engine could not be operated due to malfunction. During the early weeks of the program, operating days lost to users were a little over 4 per cent but during later periods this had been reduced to slightly over 1 per cent. It should be pointed out that these days lost included travel time for the service representative to reach the vehicle and in many cases also included the time required to ship a part from the service stores in Detroit. In addition, some portion of this lost time should be charged to the installation of advanced experimental parts for the development testing in the field. We believe that it is rather remarkable that all required service on 50 cars, scattered the length and breadth of the United States, was performed essentially by five men.
We were pleased to see a substantial reduction in the number of down-days as the program progressed, and quite satisfied with the low frequency of required maintenance on an experimental engine out on its own for the first time. But, naturally, we engineers are never completely satisfied, and will not be until maintenance requirements had become practically nil over a reasonable engin life span.
Although the actual service arrangements employed would not be applicable to a possible large volume of vehicles, the experience of the 50-car program indicates that training of personnel in the maintenance and repair of gas turbines presents no unusual problems. The principal difficulty, if there is any, is to make the trainee forget some of his piston engine knowledge. Mechanically, the power plant is less complex than most piston engines, automatic transmissions, and other current automotive components, so that the average conscientious mechanic should have no trouble performing any maintenance or repair operation which would normally be done in the field.
To this point we have seen the value of the 1.1 million miles accumulated during the 50-car program as a direct source of information on the behavior of gas turbine engines and components going through their baptism of fire. This was of great interest to us, but would remain purely academic unless the lessons learned could be translated into improvements in performance, reliability, life and manufacturing methods now incorporated in improved engines currently operating.
Vehicle response and acceleration were surprisingly good during the program, when it is considered that the engine was rated at only 130 H.P. and the car weighed about the same as a Chrysler Newport. The time required to accelerate from 0 to 60 miles per hour was generally around 12 seconds, based on an outside temperature of 85 degrees. On cooler days, greater performance could be achieved. Since then, vehicle acceleration had been substantially increased by means of a faster-acting variable nozzle actuator. In other words, the nozzle blades snap into their acceleration position much faster than they used to--something like three times faster. This is not only an obvious gain in actual response time but it makes the driver "feel" the sensation of a snappy forward motion. The dame is true of the engine braking, though at the other end of the line. The nozzle blades switch to their braking position in much less time than before and the vehicle slows down more suddenly and over a shorter distance. Additional engine braking has also been obtained by making it possible for the variable nozzle blades to go a little further than before into braking position without an increase in temperature which could cause damage.
Gas generator response--without which, incidentally, there is no vehicle response -- has also been improved ss a result of operating experience. In our first automotive turbines, back in 1954-1959 period, it took 7 seconds for the gas generator to accelerate from idle speed to full power.
In the 1962 turbine engines this was reduced to 3 seconds, and response time in the 50-car program engines was down further in the 1.5 to 2 second zone. Extensive operation established very clearly that we could increase acceleration temperature without hurting the hot parts of the engine. This, with a reduction in the inertia of the gas generator rotor, resulted in lopping off another half second in the time it takes for the gas generator to reach full speed.
Our turbine cars, located all over the nation, were exposed to all ranges of starting temperatures. Some were very low and required the use of a 24-volt battery system, which was a purely temporary field expedient. Since then, we have reduced the accessory load and the bearing losses in the gas generator to the point where dependable starting is consistently and rapidly accomplished with a 12-volt system.
The layman associates a certain quality of sound with a turbine as used in aircraft jet engines. This sound is not entirely a characteristic of the turbine but is principally caused, in aircraft jets, by the accessory drive gears. It may have served as a means of product identification, but the initial attraction must inevitably wear off, except perhaps for the "jet set", and it becomes more reasonable to follow the classic line of noise reduction. This being accomplished, particularly at low speeds, by using different types of gears, reducing the speed at which accessories run at idle, and modifying the intake filter-silencers.
In conclusion, we at Chrysler would like to take this opportunity to express one again our deepest appreciation for the encouragement received from the press and the public.
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Last edited 2-27-2009