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Diary of visit to West Coast online

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AMG-NYU No. 1^8 May 19^6

Copy No. 2
NEW YORK UNIVERSITY, APPLIED MATHEMATICS GROUP

llsKtm ,J^^^ ^^^'^ UNIVERSITY
'NSt/TUTE OF MATHEMATICAL SCIENCE
LIBRARY
4 Washington Pface, New York 3 N Y

DIAltY OP VISIT TO WEST G0A:.T i3Y JJ3 AirD -JlOiM,

APRIL 1946



April 15

Got in touch with Bureau o£ Aeronautic a liaison
people (Gojmaander Stevenson and Lieutenant Max in par-
ticular) and made su*ran{ieiTienta to 50 to Aerojet. Saw
Zwicky at Azusa in tiie aTternoon. Found him in good
heal til and in a much aore relaxed mood than we had ever
seen him before. It is cleaj? that he feela iiiuch leas
\inder pressure than h© used to. He siiowed us hla con-
tract for v/ork on the hydropulse which is very good
from his point of view since this contract permits hin
a very f^reat amount of freedom as to what he siiould do.
Noticed tliat he raay even tal:e up the problem of tlae
hydro-turbo jet. Unfortvmately, however. Aerojet haa
aa yet no contract for the aero devices. Seenlnrjly
thei"*e are some difficulties about obtaining a contract
to work on those devices.

Zwiclcy showed us through the plant at Azuaa. Vie
ware shown everything that we wanted to aee, in marked
contrast to wlxat happened when JJS and MS visited there
on a former occasion. Tlie plant is much larger than
JJS had lmap;ined it and it makes a very ^'ood Impression.
Both JJS and JKI-M were very favorably impressed both by
the people there and the facilltiea they seem to liave.
Zwicky showed ua his throe volumes of notes on his trip
throunh the German laboratories (JKIJ.I Is bringing; copies
back) and other documents in which we were interested.
Saw a compressed air driven hydropulse with a jet tube
about 4 feet long and a fev/ Inches in diameter which
developed a tlirust of 150 pounds. Pressure curves



NEW YORK UNIVERSITY, APPLIED MATHEMATICS GROUP



indicate desirability of timing injection of air to
synchronize with pressure pulse due (apparently) to rar/i
effect of inflowin.'j; water. Tlieoretical study seeris de-
sirable. Sugr.Qst Prled-Tian emd some associate visit
Aerojet to discuss theory some time within next 6
months. Zwlolcy spoke of desirable feat^aros of alwainmn
boro-hydride to replace the relatively inexpensive but
slowly reacting sodium potassium alloy as a fuel for
hydropulses . Saw various earlier models of hydropulse
components as well as various kinds of aeropulses in-
cluding an automatic rotary air- valve type, a heater
and a recent Schmidt pulse- jet (which Zwicky broun;ht
back with him from Germany) . This last type employs a
conical banlc of reed valves (air intake), special types
of fuel Injectors and a diverging jet- tube with a re-
sulting hl;»h efficiency and long life; it is probably
tho first step in an important development in pulse- jets.
Schmidt was Tsrorkinij on a comprehensive extension of the
field of pulse-jet devices when VE day arrived. He had
plans for complicated free piston pulse- jet devices for
use in the (general field of propulsion, Zwiclcy was in-
terested in controlled coraWstion - he sees five sta^^es
of design for combustion: (1) Combustion In quiescent
gas, (2) Combustion in arbitrarily turbulent gas, (-3)
Combustion with aero-dynamically developed turbulence,
(4) combustion with thermally developed turbulence, (5)
Purely chemical control. Zwicky plans use (in How
Mexico) of a rocket noimted on V2 as two sta.je propul-
sive device to hit moon (in relatively near future) to
make telescopic study of dust developed by Inipact. V/e
will return on Wednesday to Aerojet to spend the day.

April 16

"vVent to GalTech to speak briefly with Swlolcy and
then went to talk with Tsien. Told Tslon that Priodrlchs



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NEW YORK UNIVERSITY. APPLIED MATHEMATICS GROUP



has talcen up the work on the supersonic airroil ai^ain
and hopes to carry that tlirough now. Learned that
Tslen is tryln^^j to initiate raore abstract research than
he did dtirln.]; the war, with particular reference to low
density aerodynamics Involvinc hijher order derivatives
in viscosity, heat flow and diffusion. Told Tsien we
had heard he raisht be coning to Princeton but did not
get much of a reaction except the general impression
tliat Tsien would not be averse to c^ln^j, to the East.
Had lunch with Tsien who talked mostly about ITexoaarm ' a
plans for calculating machines. Tsien disapproves of
these plans principally because he feels that ITe\iKiann
claims more for the machine than it can deliver. He
also feels that ITeumann therefore has a tendency to
minimize the theoretical \vork that lias to be done, say
to solve some of the basic problems in gas dynamics.

JICLU spent most of ai'ternoon preparing; for ne.it
day's talk to Aerojet people and trip to Inyokern.

JJ3 saw Epstein in the afternoon. Learned that MS
was considered for a position but Bohnenblust ;ot the
job. (Zwiclcy stated, however, that they took Bolinenblust
to manage landergradixate affairs, not to take Bato^nan's
place, and for tlmt H3 would not be the man anyway, in
JJS opinion.)

iTpstein then told of Karman's support of the idea
of having LIS go to GIT. Epstein feels that there still
might be a place for JUS there and recommends that KOP
and JJS write strong letters about this to him or to
Bell. Epstein then told of his work on elastic shells
wiiich is interesting. He may have beaten S. Reisner in
the extension of the Kirchoff thin plate theory. Told
him of i'lOP's recent work. iHpstoin no longer does war
work and v/ants to get back to quantum mechanics as rapidly



NEW YORK UNIVERSITY, APPLIED MATHEMATICS GROUP

as possible. He doea not have lauch i'alth in the Navy as a
supporter of raaearoh - nor much faith in the national
Science J^'oundation either.

Later in the arternoon JJ3 .ju..< i-annan »^.^ vvu.a Vux j
jovial and friendly. Spoke about Shlffraan and mentioned
the possibility Ox" a job for him in the EliGlneerinrj; School,
Do not thinlc this would be a proper Job for IS and recoramended
DePritoa instead. Have to see ■^. ^, Linvall, Chairman of the
Ensineerins Division, later on i>^ i.all: to him about this.
Linvall said Karman was leaving for the East the next day.
Told Karraan we had heard that he Intended to leave the West
Coast to stay permanently in the East and aslred him if that
v/ere true. He said that he was oin, which JICTjM finds liard to believe
since part of tt (=y*pdY) is used in conpresaion heating
of adjacent layers of the jet jases (in contrast v/ith the
casG In ordinar^^ internal corabuation enf^ines for v/hich
cntlialpy is of minor importance). Zwicky considers the
followinr cases as practical extremes:



depends markedly on the au.'smontation /Q
but not on tiie air speed u .

(2) u^^ -* 00 , y5 - 0, ti^ = 1; then I^p -

u

7^ ^ -^^ Tidilo'-* "06 3 not depend on the

au»;;nentation and which varies nore
strongly with Ae than in the first case.

Zwiclcy a'rrees that Prledrich's calctilatlons are correct
but do not consider contributions from u and /Q , More-
over he probably somewhat confixses his "thermodynamic
cycle efficiency" -^ with Friedrich's notions of speci-
flc thrust efficiency, since he kept stressing: the rela-
tively minor changes in T that he expected on the basis
of practical possibilities for Increaslnr^ the thermo-
dynaraic cycle efficiency. In particular he stressed the
fact tiiat for the explicit cycle mentioned abovo (see



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NEW YORK UNIVERSITY. APPLIED MATHEMATICS GROUP



derinltion of At) the efficiency -^ la only about 53
percent for p^ » 12 atmosphores, and that in practice it
is hard to get nuch more tiian the considerably less effi-
cient pressure P3 = 2 atmospheres, ills main thesis
seemed to be tliat efficiency should be considered only in
connection with all factors concerned. JKLM feels tliat
Zwicky believes too much in his universal tiirust equation
but that the only effective procedure would be to devise
a more scientific substitute before attemptin,: to discuss
the matter v/lth him.

One of the objects In visiting Zwlcky was to Infom
him that KOP and JJS tto lon-er wished to work on the scni-
engineering problems connected with the hydropulse and
the aeropulae, since v;e feci tliat we are not particularly
suited for this kind of work. However, JKLil, Frled2aan>
and possibly others in the croup feel differently, said of
course they may do what they like. JKLM and his c^oup
particularly are very much Interested in extondlnc their
work on the aero devices. Swlclcy did not seem either
surprised or annoyed, but simply asked whether, for
example, KOP would continue basic research In gas
dynamics. Of course he v/as reassured that that was the
case. (JlOiM noted that JJ3 and Zwiclry get along together
exceptionally well and that Zwlclo,r'3 attitude entirely
friendly towards the AIJG in general; possibility of JJS
and Zwiclcy going together to Paris conference on mechanics.)
Zwlcky, and all Iiis group at Aerojet, would like to con-
centrate on what they consider to be basic research and
they feel tlmt they arc to a certain degree prevented
from doing so just because Aerojet Is an Industrial con-
cern. In other words, the past history of Aerojet influ-
ences the llavy in an adverse way with respect to getting
contracts for doing basic research, r/e feel that this
policy Is not sensible and that Aerojet has a group of



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NEW YORK UNIVERSITY, APPLIED MATHEMATICS GROUP



people who could be very useful in carryin;; out basic re-
searches for the intermittent motors and other aero de-
vices.

Flew from Burbanic to san Francisco . Arrived at
Berkeley In the evening where we were met by Lew^'' who iiad
dinner with us.

rook a uixj JxT. Lewy tool: us across the bay to Mt.

Tamalpals . From this mountain one looks on one side on

the Pacific and on the other over the Golden Gate to iJan

Francisco. Have rarely spent an afternoon more agreeably.

April 25

Discussed Lewy's work in the morning. He iias solved
the sloping beach problem for angles ^ tr with p any odd
Integer and q any intei^er audi that 2q > p. The thing is
very difficult, however, and I was not able to master it
in the time I was there, particularly since Lowy load only
a handwritten manuscript - a typical Lewy raanuscript. He
expects to publish this before long in the Bulletin.
Lunched with Lewy, Robinson and other membei's of the


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Online LibraryJames Johnston StokerDiary of visit to West Coast → online text (page 1 of 2)