419:, has the Kantrowitz limit as a fundamental design criterion. Attempting to pass a high-speed passenger-pod through a very low pressure tube runs squarely into the Kantrowitz fluid flow limit. Historically, the solutions to working within the limit have been "go fast" and "go slow". A major innovation in the Hyperloop proposal provides a novel third approach to remain below the Kantrowitz limit while still moving at high-subsonic velocities: adding a front-end inlet compressor to actively transfer high-pressure air from the front to the rear of the high-speed transport capsule, and thus bypassing much of the air that would have resulted in the
518:
408:. When the absolute pressure of the vacuum is decreased further, the flow speed will not increase. This is the Kantrowitz Limit, which limits the mass flow because the velocity is limited to the speed of sound, and the area, inlet pressure and density are all fixed. Aircraft jet engines are very much affected by this limit, once the inlet flow speed gets to Mach 1 the mass flow rate is limited, regardless of how much suction the engine creates.
331:
214:, which were able to produce the extremely hot gases needed to simulate atmospheric re-entry from orbital speeds, thereby solving the critical nose cone re-entry heating problem and accelerating the development of recoverable spacecraft. He was AERL's director, chief executive officer, and chairman until 1978 when he took on a professorship at
299:, "We could have developed all this in the 60s and 70s, but we went another path. Arthur Kantrowitz tried to convince Kennedy's people that the best way to the Moon was through development of manned space access, a von Braun manned space station, and on to the Moon in a logical way that left developed space assets."
283:
Another contribution to science was the stagnation-point flow experiment in which processes of initial interaction of fresh flowing blood with an artificial surface can be directly visualized under a high-power microscope. This technique has become an important method for experimentally studying this
411:
Next, consider the nozzle connected to a compressed air supply. With a pressure ratio of about 2, the flow becomes choked, and cannot exceed the speed of sound. But the density and resultant mass flow rate can be increased by increasing the inlet pressure. The greater the pressure, the greater the
427:. The flow in the smaller duct through the capsule is also subject to the Kantrowitz Limit, this is relieved by increasing the pressure and the density to achieve the required mass flow. In the Hyperloop alpha design of 2013, the air-inlet pump also provides a low-friction
465:
Kantrowitz was an honorary trustee of the
University of Rochester, an honorary life member of the Board of Governors of The Technion, and an honorary professor of the Huazhong Institute of Technology, Wuhan, China. Kantrowitz also served on the Board of Advisors for the
287:
Kantrowitz, as an advocate of the separation of science and technology from political or ideological concerns, first proposed in 1967 the creation of an
Institution for Scientific Judgment, commonly referred to as the Science Court, to assess the state of knowledge in
446:, American Association for the Advancement of Science, American Astronautical Society, American Institute of Aeronautics and Astronautics (honorary), American Physical Society, American Institute for Medical and Biological Engineering and member of the
995:
1040:
1035:
292:
of importance to public policy. He further developed the
Science Court as its Task Force Chairman in President Ford's Advisory Group on Anticipated Advances in Science and Technology, 1975–1976.
269:, patent application, 1941. In 1950, he invented a technique for producing the supersonic source for molecular beams; this was subsequently used by chemists in research that led to two
789:
The ability of the classical
Kantrowitz limit to predict the restart contraction ratio was assessed, and it was shown to be applicable for the hard unstart/restart configurations.
404:
Consider a nozzle connected to a vacuum source. As the pressure ratio gets to about 2, the flow through the nozzle will approach the local speed of sound, and the flow becomes
1030:
704:
1010:
280:. The balloon pump is a temporary cardiac assist device which has been used worldwide on three million people. The device was used on his own failing heart.
188:
96:
1020:
451:
412:
density, and the greater the mass flow. So, while
Kantrowitz limits the maximum gas velocity, it does not apply any fixed limit to the mass flow rate.
1025:
1000:
832:
443:
1015:
1005:
477:
Kantrowitz held 21 patents and wrote or co-authored more than 200 scientific and professional papers and articles. He also co-authored
415:
A recent high-speed transportation option for rapid transit between populous city-pairs about 1,000 miles (1,600 km) apart, the
815:
688:
561:
539:
203:
reactor. The name was deliberately chosen to disguise its purpose, but it was eventually found out and the funding was cancelled.
210:
for the next ten years and later founded the Avco-Everett
Research Lab (AERL) in Everett, Massachusetts, in 1955. He developed
447:
970:
The best weapon of a dictatorship is secrecy, but the best weapon of a democracy should be the weapon of openness. —Niels Bohr
250:
to launch bulk payloads into orbit, using energy from ground-based lasers to increase exhaust velocity and thereby reduce the
163:
Kantrowitz was born in New York City on
October 28, 1913. His mother was a costume designer and his father ran a clinic in
920:
803:
261:
diffusers and supersonic compressors in the early 40s, which has since been applied to jet engines. He invented the
870:
144:
928:
497:
277:
532:
526:
289:
262:
941:
543:
420:
886:
Johnson, John Jr. (December 15, 2008). "Arthur R. Kantrowitz, 1913–2008: Noted physicist and inventor".
839:
675:
485:
459:
176:
484:
Kantrowitz died at age 95, November 29, 2008, while visiting relatives in New York. He had suffered a
265:
in 1939, used in soaring planes, and is the co-inventor of an early scheme for magnetically contained
191:(NACA), work he would continue for ten years. While obtaining his Ph.D., Kantrowitz was supervised by
990:
985:
243:
239:
965:
467:
196:
187:
During his graduate studies at
Columbia, Kantrowitz started working as a physicist in 1936 for the
152:
68:
284:
vital interaction and led to a variety of circulatory prostheses, including the artificial heart.
659:
590:
207:
168:
101:
723:
680:
585:
912:
888:
811:
684:
431:
215:
172:
106:
772:
367:
316:
247:
219:
654:
629:
375:
296:
251:
231:
745:
586:"Arthur R. Kantrowitz, Whose Wide-Ranging Research Had Many Applications, Is Dead at 95"
471:
398:
383:
266:
330:
979:
192:
48:
953:
17:
710:
371:
235:
200:
945:
764:
932:
428:
424:
405:
308:
270:
276:
In the 1960s and 1970s, he led the design and development at AERL of the first
387:
379:
312:
258:
211:
904:
604:
455:
416:
164:
140:
125:
315:
and near-supersonic inlet velocities. The concept has become known as the
133:
129:
944:. American Institute of Beamed Energy Propulsion (AIBEP). Archived from
862:
776:
218:. From 1956 to 1978 he also served as a vice president and director of
148:
454:
and
International Academy of Astronautics. In 1953–1954, he held both
307:
Kantrowitz is known for development of a theoretical concept of fluid
394:
393:
Two examples will explain the effect of the
Kantrowitz Limit on a
500:– practical ground transport vehicle prototypes dealing with the
511:
325:
147:. He earned his B.S., M.A. and, in 1947, his Ph.D. degrees in
254:. His concepts on laser propulsion were published in 1988.
124:(October 20, 1913 – November 29, 2008) was an American
401:= Inlet Velocity multiplied by Area multiplied by Density.
863:"Biographies of Aerospace Officials and Policymakers, K-N"
434:
for traveling at over 700 mph (1,100 km/h).
996:
Members of the United States National Academy of Sciences
706:
Proceedings of the International Conference on Lasers '87
342:
230:
Kantrowitz's interdisciplinary research in the area of
462:
Fellowships at Cambridge and Manchester Universities.
242:
and to the development of high-efficiency, high-power
630:"Alumni Award Recipients | School of General Studies"
1041:
Columbia Graduate School of Arts and Sciences alumni
1036:
Columbia University School of General Studies alumni
655:"Dr. Adrian Kantrowitz, Cardiac Pioneer, Dies at 90"
89:
81:
64:
56:
41:
34:
663:, November 19, 2008. Retrieved November 19, 2008.
942:"Arthur Kantrowitz, Founder of Laser Propulsion"
765:"Starting characteristics of supersonic inlets"
594:, December 9, 2008. Retrieved December 9, 2008.
171:from old radio parts, working with his brother
763:Van Wie, D.; Kwok, F.; Walsh, R. (July 1996).
199:, the first known attempt to build a working
8:
470:, an organization devoted to preparing for
386:, both when operating at high-subsonic and
189:National Advisory Committee for Aeronautics
97:National Advisory Committee for Aeronautics
31:
580:
578:
562:Learn how and when to remove this message
1031:Fellows of the American Physical Society
802:Curran, E. T.; Murthy, S. N. B. (2001).
525:This article includes a list of general
195:. In 1938, he began construction of the
873:from the original on September 28, 2006
574:
940:Pakhomov, Andrew (November 29, 2008).
838:. SpaceX. pp. 3–4. Archived from
175:(who would go on to perform the first
713:, Ed. (STS Press, Mc Lean, VA, 1988).
444:American Academy of Arts and Sciences
238:led to contributions in the field of
7:
1011:Thayer School of Engineering faculty
905:"The Papers of Arthur R. Kantrowitz"
909:Rauner Special Collections Library
531:it lacks sufficient corresponding
25:
1021:DeWitt Clinton High School alumni
246:. He first suggested a system of
516:
329:
252:propellant-to-payload mass ratio
1026:20th-century American engineers
1001:Engineers from New York (state)
724:"Kantrowitz, Arthur, 1913-2008"
481:, 1958, Princeton Univ. Press.
448:National Academy of Engineering
442:Kantrowitz was a fellow of the
831:Musk, Elon (August 12, 2013).
673:Shetterly, Margot Lee (2016).
167:. As a child, Arthur built an
1:
370:has many applications in the
479:Fundamentals of Gas Dynamics
452:National Academy of Sciences
257:His early research included
1057:
1016:Jewish American scientists
1006:Cornell University faculty
679:. William Morrow. p.
145:DeWitt Clinton High School
929:Encyclopedia Astronautica
498:Hyperloop pod competition
278:intra-aortic balloon pump
115:
74:
954:"The Weapon of Openness"
290:scientific controversies
226:Scientific contributions
122:Arthur Robert Kantrowitz
546:more precise citations.
263:total energy variometer
206:He went on to teach at
179:in the United States.)
85:physics and engineering
750:www.jerrypournelle.com
139:Kantrowitz grew up in
867:NASA History Division
804:"7 "Scramjet inlets""
488:on the previous day.
322:Technical description
958:Foresight Background
948:on February 7, 2009.
605:"Kantrowitz, Arthur"
240:magnetohydrodynamics
18:Arthur R. Kantrowitz
966:Foresight Institute
921:"Arthur Kantrowitz"
845:on January 28, 2016
808:Scramjet Propulsion
777:10.2514/6.1996-2914
726:. Dartmouth Library
703:A. Kantrowitz, in
468:Foresight Institute
197:Diffusion Inhibitor
153:Columbia University
143:and graduated from
69:Columbia University
935:on March 27, 2003.
660:The New York Times
591:The New York Times
397:. For both cases,
341:. You can help by
208:Cornell University
169:electrocardiograph
102:Cornell University
913:Dartmouth College
889:Los Angeles Times
833:"Hyperloop Alpha"
810:. Vol. 189.
746:"ACCESS TO SPACE"
653:Hoffman, Jascha.
584:Overbye, Dennis.
572:
571:
564:
438:Honors and awards
432:suspension system
359:
358:
317:Kantrowitz limit.
216:Dartmouth College
119:
118:
107:Dartmouth College
76:Scientific career
60:November 29, 2008
36:Arthur Kantrowitz
27:American engineer
16:(Redirected from
1048:
972:
949:
936:
931:. Archived from
916:
893:
882:
880:
878:
855:
854:
852:
850:
844:
837:
828:
822:
821:
799:
793:
792:
785:
783:
760:
754:
753:
742:
736:
735:
733:
731:
720:
714:
701:
695:
694:
670:
664:
651:
645:
644:
642:
640:
626:
620:
619:
617:
615:
601:
595:
582:
567:
560:
556:
553:
547:
542:this article by
533:inline citations
520:
519:
512:
502:Kantrowitz limit
368:Kantrowitz limit
354:
351:
333:
326:
303:Kantrowitz limit
248:laser propulsion
220:Avco Corporation
177:heart transplant
45:October 20, 1913
32:
21:
1056:
1055:
1051:
1050:
1049:
1047:
1046:
1045:
976:
975:
952:
939:
919:
903:
900:
885:
876:
874:
861:
858:
848:
846:
842:
835:
830:
829:
825:
818:
801:
800:
796:
781:
779:
762:
761:
757:
744:
743:
739:
729:
727:
722:
721:
717:
702:
698:
691:
672:
671:
667:
652:
648:
638:
636:
634:gs.columbia.edu
628:
627:
623:
613:
611:
609:history.aip.org
603:
602:
598:
583:
576:
568:
557:
551:
548:
538:Please help to
537:
521:
517:
510:
494:
440:
364:
355:
349:
346:
339:needs expansion
324:
305:
297:Jerry Pournelle
232:fluid mechanics
228:
185:
161:
111:
65:Alma mater
52:
46:
37:
28:
23:
22:
15:
12:
11:
5:
1054:
1052:
1044:
1043:
1038:
1033:
1028:
1023:
1018:
1013:
1008:
1003:
998:
993:
988:
978:
977:
974:
973:
950:
937:
917:
899:
898:External links
896:
895:
894:
883:
857:
856:
823:
816:
794:
755:
737:
715:
696:
689:
676:Hidden Figures
665:
646:
621:
596:
573:
570:
569:
524:
522:
515:
509:
506:
505:
504:
493:
490:
472:nanotechnology
439:
436:
399:Mass flow rate
363:
360:
357:
356:
336:
334:
323:
320:
304:
301:
267:nuclear fusion
227:
224:
184:
181:
160:
157:
117:
116:
113:
112:
110:
109:
104:
99:
93:
91:
87:
86:
83:
79:
78:
72:
71:
66:
62:
61:
58:
54:
53:
47:
43:
39:
38:
35:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1053:
1042:
1039:
1037:
1034:
1032:
1029:
1027:
1024:
1022:
1019:
1017:
1014:
1012:
1009:
1007:
1004:
1002:
999:
997:
994:
992:
989:
987:
984:
983:
981:
971:
967:
963:
959:
955:
951:
947:
943:
938:
934:
930:
926:
922:
918:
914:
910:
906:
902:
901:
897:
891:
890:
884:
872:
868:
864:
860:
859:
841:
834:
827:
824:
819:
817:9781600864414
813:
809:
805:
798:
795:
791:
790:
778:
774:
770:
766:
759:
756:
751:
747:
741:
738:
725:
719:
716:
712:
708:
707:
700:
697:
692:
690:9780062363596
686:
682:
678:
677:
669:
666:
662:
661:
656:
650:
647:
635:
631:
625:
622:
610:
606:
600:
597:
593:
592:
587:
581:
579:
575:
566:
563:
555:
552:December 2008
545:
541:
535:
534:
528:
523:
514:
513:
507:
503:
499:
496:
495:
491:
489:
487:
482:
480:
475:
473:
469:
463:
461:
457:
453:
449:
445:
437:
435:
433:
430:
426:
422:
421:dynamic shock
418:
413:
409:
407:
402:
400:
396:
391:
389:
385:
381:
377:
373:
369:
361:
353:
344:
340:
337:This section
335:
332:
328:
327:
321:
319:
318:
314:
310:
302:
300:
298:
295:According to
293:
291:
285:
281:
279:
274:
272:
268:
264:
260:
255:
253:
249:
245:
241:
237:
233:
225:
223:
221:
217:
213:
209:
204:
202:
198:
194:
193:Edward Teller
190:
182:
180:
178:
174:
170:
166:
158:
156:
154:
150:
146:
142:
137:
135:
131:
127:
123:
114:
108:
105:
103:
100:
98:
95:
94:
92:
88:
84:
80:
77:
73:
70:
67:
63:
59:
55:
50:
49:New York City
44:
40:
33:
30:
19:
969:
961:
957:
946:the original
933:the original
924:
908:
887:
875:. Retrieved
866:
847:. Retrieved
840:the original
826:
807:
797:
788:
787:
780:. Retrieved
769:AIAA 96-2914
768:
758:
749:
740:
728:. Retrieved
718:
711:F. J. Duarte
705:
699:
674:
668:
658:
649:
637:. Retrieved
633:
624:
612:. Retrieved
608:
599:
589:
558:
549:
530:
501:
486:heart attack
483:
478:
476:
464:
441:
414:
410:
403:
392:
390:velocities.
372:gas dynamics
365:
362:Applications
347:
343:adding to it
338:
309:choke points
306:
294:
286:
282:
275:
271:Nobel Prizes
256:
236:gas dynamics
229:
205:
201:fusion power
186:
162:
138:
121:
120:
90:Institutions
75:
29:
991:2008 deaths
986:1913 births
639:January 29,
614:January 29,
544:introducing
429:air-bearing
425:choked flow
406:choked flow
380:jet engines
350:August 2013
212:shock tubes
980:Categories
877:August 15,
849:August 14,
782:August 13,
527:references
508:References
460:Guggenheim
388:supersonic
376:inlet flow
313:supersonic
259:supersonic
159:Early life
925:Biography
730:April 26,
456:Fulbright
417:Hyperloop
165:the Bronx
141:The Bronx
126:scientist
968:. 1989.
871:Archived
492:See also
134:educator
130:engineer
540:improve
423:of the
384:rockets
149:physics
814:
687:
529:, but
395:nozzle
244:lasers
183:Career
173:Adrian
132:, and
82:Fields
892:: B5.
843:(PDF)
836:(PDF)
151:from
879:2006
851:2013
812:ISBN
784:2013
732:2023
685:ISBN
641:2022
616:2022
458:and
450:and
382:and
378:for
366:The
234:and
57:Died
51:, US
42:Born
773:doi
374:of
345:.
311:at
982::
964:.
960:.
956:.
927:.
923:.
911:.
907:.
869:.
865:.
806:.
786:.
771:.
767:.
748:.
709:,
683:.
681:54
657:,
632:.
607:.
588:,
577:^
474:.
273:.
222:.
155:.
136:.
128:,
962:4
915:.
881:.
853:.
820:.
775::
752:.
734:.
693:.
643:.
618:.
565:)
559:(
554:)
550:(
536:.
352:)
348:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.