SP-4302 Adventures in Research: A History of Ames Research Center 1940-1965

 

PART II : A NEW WORLD OF SPEED : 1946-1958

1958

 

14

People and Events

 

[277] SINCE major changes in NACA were expected shortly, the Ames organization during this period was left largely as it had been. For the most part, changes were limited to those necessitated by staff resignations. The ferment of the times was such, in 1958, as to encourage research people to feel that rich opportunities might exist elsewhere. A group composed of Jack Stalder, Morris Rubesin left the laboratory in June to form a private research and consulting firm. This departure represented a severe blow to Ames because all these men had demonstrated a high degree of competence and originality in aeronautical research.

Jack Stalder, though a solid hardheaded engineer, had exhibited farsightedness in research planning that put him at the disadvantage of appearing ahead of his time. Actually he was not ahead of it-only in the lead- and his judgments, though advanced, were sound. Morris Rubesin had demonstrated rare originality in his theoretical heat-transfer research, and Jack Nielsen had shown solid competence in dealing with the theory of aerodynamic wing-body interference. Wallace Davis was respected not only for his important contributions in the field of supersonic inlets but also for his managerial abilities, demonstrated as head of the group of sophisticated scientist-engineers who individually had, by uncertain circumstance, gravitated to the 1- by 3-Foot Tunnel Section.

After the departure of Stalder and his coconspirators, the 1- by 3-foot tunnel group was put under Richard Scherrer and the 2- by 2-foot tunnel group under Perry Polentz. Both groups were classified as sections and were incorporated into a new Fluid Mechanics Branch of which Bradford Wick was appointed Chief. In a somewhat similar fashion the sections operating the low-density and the heat-transfer tunnels were completely integrated to form a new Low-Density and Heat-Transfer Wind Tunnels Branch which was placed under the command of Glen Goodwin.

Another serious loss to Ames during 1958 was the resignation in October of Milton Van Dyke, an original and highly talented mathematician. He [278] left Ames to join the faculty of Stanford University, after completing some outstanding work on the blunt-nose problem. Also in October, Donald Wood, in ill health, relinquished his position as Chief of the Theoretical and Applied Research Division (TARD) and was made Technical Assistant to the Associate Director. Robert Crane, who had been Assistant Chief of TARD under Wood, moved up to fill the gap that Wood left.

In March 1958 there was a noteworthy technical conference on "High Speed Aerodynamics," and in July what appeared might be the final Ames Inspection was held. Both events emphasized the space-related research that had been underway in NACA and together gave convincing evidence of NACA's qualifications for leading the Nation's space research effort. The Science Trophy of the Air Force Association in 1958 was presented to Harvey Allen for his conception of the blunt-nose principle and its application to the design of reentry bodies.

None of the supporting activities at Ames bore a more intimate relationship to the principal function of the Laboratory than did the work of the Instrument Research Division. The intimacy, indeed, was all the more apparent as instrument development at Ames often partook of the nature of research. The instruments developed were generally the product of a close collaboration between representatives of instrument and aeronautical research groups. The general purpose of the developed instruments was to facilitate the quantitative determination of physical phenomena of interest in the experimental research carried on by the Laboratory. As the aeronautical research of the Laboratory became more complex, so also did the task of the instrument research man. Never-ending pressure was placed on him to produce smaller and more reliable instruments which more rapidly and accurately would measure a wider variety of physical phenomena under more adverse conditions. The challenge was tremendous.

Instrument work at Ames was initiated in 1940 by James Kelley who for many years had done similar work at Langley. Kelley's efforts were soon augmented by those of Howard Kirschbaum. In 1943, Kirschbaum was put in charge of an Instrument Development Section which was shortly incorporated into a new Service Division headed by James White-another Langley emigre. White's group in 1953 became the Research Instrumentation and Engineering Services Division, of which Jeff Buck was appointed Assistant Chief. In 1955 the Engineering Services Division was split off under Jeff Buck, leaving Jim White in charge of a newly constituted Instrument Research Division. Of this Division, Howard Kirschbaum was made Executive Engineer.

By the time the new Instrument Research Division had been created, the scope of instrument development had so expanded that considerable specialization was necessary. Inasmuch as there had always been a dissimilarity between the instruments required for flight research and those required for wind-tunnel research, it was natural that there should, within the [279] Instrument Research Division, be formed a Flight Instrument Research Branch and a Wind Tunnel Instrument Research Branch. There were also created a Mechanical Instrument Branch under Jim Kelley and an Electronic Instrument Branch under Leonard Fairfield to deal with the construction, calibration, maintenance, and installation of the instruments conceived by the two instrument research branches.

Dr. G. Allan Smith was made Chief of the Flight Instrument Research Branch, with Taft Wrathall, an oldtimer in instrument work at Ames, as his assistant. Taft resigned soon after his appointment and his position was filled by John Foster. The task confronting Smith and Foster became increasingly difficult as flight research moved into areas of greater sophistication. The two men, in meeting this challenge, made major contributions to the development of variable-stability airplanes and also to the development of the specialized equipment required for studies of tracking, target simulation, and automatic control.

The development of wind-tunnel instrumentation was an activity which grew in complexity and volume, and before the end of 1958 represented a rather large part of the total instrument development effort. Wind-tunnel instrument development work was originally carried out by Howard Kirschbaum, who later was aided by Taft Wrathall and John Dimeff. When the new Instrument Research Division was formed, John Dimeff was made Chief, and William Kerwin, Assistant Chief, of the Wind Tunnel Instrument Research Branch that was created within the Division.

In the early days of the Ames Laboratory, wind-tunnel instrumentation was fairly simple. Wind-tunnel models and their heavy supporting systems were mounted on several large scales, the individual readings of which could be taken by eye or printed on a paper tape. Pressure distributions were measured by huge banks of liquid manometer tubes which were photographed at appropriate intervals. The task of working up the data from such instrumentation required much human labor and was very tedious.

Around 1942 the electrical resistance wire strain gage reached a useful stage of development. This small device proved to have great utility in the measurement of the hinge moments of control surfaces or the bending stresses occurring in the wings or tails of airplanes or airplane models. The response of the wire strain gage was very fast but could readily be followed by the galvanometer elements of the multichannel oscillograph which had recently come into use. It was not long before wire strain gages were being used in a new type of "strain-gage balance" capable of measuring, simultaneously, all six of the force and moment components applied by the airstream to a wind-tunnel model. The strain-gage balance was so small that it could be mounted entirely within the test model. Its development permitted the elimination of the conventional bulky support struts which, as wind-tunnel speeds increased, had become an intolerable nuisance. The support system that now came into vogue was composed of a single shaft, or sting, which....

 


[
280]

From left to right: John V. Foster, Howard W. Kirschbaum, and John Dimeff.

 

....entered the model from the rear and was attached firmly to the strain-gage balance. Liquid multiple manometers continued to be used for a while but later were largely replaced by tiny pressure cells which generated an electric current pattern that could be recorded with an oscillograph or displayed on the face of a cathode-ray oscilloscope.

Most wind-tunnel measurements now appeared as electric currents or voltages, and this circumstance led to the mechanization of data handling and workup. It was shortly found that the output of the wind-tunnel bal-....

 


lnternal strain-gage balance.

lnternal strain-gage balance.

 

[281] ....-ances could be transferred directly to punched cards or punched paper tape which later could be fed, for data workup, into one of the new electronic computers then coming into use. Still later, as mentioned in an earlier section, the wind-tunnel signals were transmitted through wires directly to the computer with no intermediate card system. The wind-tunnel data, having been converted to coefficient form by the computer, were retransmitted to the wind tunnel and automatically plotted. With this so-called "on-line" system it was possible for the wind-tunnel operator to watch the data being plotted as the test proceeded and to alter his test plan as necessary.

The problems facing John Dimeff and his staff became an order of magnitude more difficult with the development at Ames of low-density and high-temperature wind tunnels and intermittent-flow facilities such as the SSFF tunnel and the gun ranges. X-ray and other techniques were devised for investigating low-pressure flows, while schlieren and interferometric methods were developed for qualitative and quantitative airflow studies at higher pressures. Also, a requirement had recently developed for radiometric equipment with which to analyze the glowing wakes of high-velocity test models. The Wind Tunnel Instrument Research Branch had; moreover, been involved in the development of the highly specialized and extremely precise instrumentation required for the facilities in which models were launched by means of guns. It also had collaborated with Ben Beam of the 12-foot tunnel in the development of his famous dynamic-stability balance and with Don Smith of the same tunnel in the development of a supersensitive balance for the direct measurement of skin friction.


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