1
00:00:00,000 --> 00:00:02,736
AEROSCIENCES EVALUATION AND TEST

2
00:00:02,736 --> 00:00:04,437
CAPABILITIES PORTFOLIO

3
00:00:04,704 --> 00:00:05,672
IS INVESTING IN

4
00:00:05,672 --> 00:00:07,140
A CAPABILITY CHALLENGE

5
00:00:07,140 --> 00:00:08,641
DESIGNED TO ASSESS THE ABILITY

6
00:00:08,641 --> 00:00:10,810
OF COMPUTATIONAL FLUID DYNAMICS

7
00:00:10,810 --> 00:00:12,178
TO ADDRESS AEROSCIENCE

8
00:00:12,178 --> 00:00:13,513
PREDICTION REQUIREMENTS

9
00:00:13,513 --> 00:00:15,415
AT HIGH SUPERSONIC SPEEDS.

10
00:00:17,017 --> 00:00:18,451
TO DO THIS, A SERIES OF

11
00:00:18,451 --> 00:00:19,719
WIND TUNNEL TESTS

12
00:00:19,719 --> 00:00:21,654
AND IDENTICAL CFD ANALYSIS

13
00:00:21,654 --> 00:00:23,189
WILL BE CONDUCTED AND COMPARED

14
00:00:23,189 --> 00:00:24,691
TO DETERMINE THE ACCURACY

15
00:00:24,691 --> 00:00:26,493
OF CFD RELATIVE TO

16
00:00:26,493 --> 00:00:28,294
WIND TUNNEL TESTING.

17
00:00:28,995 --> 00:00:30,363
THE INFORMATION GAINED

18
00:00:30,363 --> 00:00:32,032
FROM THIS CHALLENGE CAN BE USED

19
00:00:32,032 --> 00:00:33,967
TO OPTIMIZE FUTURE TESTING

20
00:00:33,967 --> 00:00:35,402
AND LEAD TO A MORE EFFICIENT

21
00:00:35,402 --> 00:00:37,971
UTILIZATION OF OUR CAPABILITIES.

22
00:00:39,539 --> 00:00:40,640
ONE COMPARISON WAS

23
00:00:40,640 --> 00:00:41,875
THE CONTROL SURFACE

24
00:00:41,875 --> 00:00:42,909
EFFECTIVENESS

25
00:00:42,909 --> 00:00:44,411
FOR A HYPERSONIC ENTRY

26
00:00:44,411 --> 00:00:45,345
DESCENT VEHICLE

27
00:00:45,345 --> 00:00:47,347
FOR LANDING HUMANS ON MARS.

28
00:00:47,747 --> 00:00:49,282
THE MIDLIFT TO DRAG RATIO,

29
00:00:49,282 --> 00:00:51,684
CobraMRV.

30
00:00:52,485 --> 00:00:54,320
THIS VEHICLE HAS TWO BODY FLAPS

31
00:00:54,320 --> 00:00:55,722
FOR AERODYNAMIC CONTROL

32
00:00:55,722 --> 00:00:56,890
DURING DESCENT THROUGH

33
00:00:56,890 --> 00:00:58,191
THE MARTIAN ATMOSPHERE.

34
00:00:58,758 --> 00:01:00,193
THESE FLAPS ALLOW THE VEHICLE

35
00:01:00,193 --> 00:01:01,861
TO ADJUST ITS FLIGHT PATH

36
00:01:01,861 --> 00:01:03,163
VERY PRECISELY

37
00:01:03,163 --> 00:01:05,198
BEFORE RETROROCKETS TAKE OVER

38
00:01:05,198 --> 00:01:06,566
TO FURTHER SLOW AND MANEUVER

39
00:01:06,566 --> 00:01:08,301
THE VEHICLE FROM MACH 2

40
00:01:08,301 --> 00:01:10,336
DOWN TO A SOFT LANDING.

41
00:01:11,504 --> 00:01:12,906
WE ARE PARTICULARLY INTERESTED

42
00:01:12,906 --> 00:01:14,607
IN HOW WELL CFD PREDICTS

43
00:01:14,607 --> 00:01:16,242
THE MEASURED FORCES AND MOMENTS

44
00:01:16,242 --> 00:01:17,544
GENERATED BY DIFFERENT

45
00:01:17,544 --> 00:01:18,812
FLAP DEFLECTIONS,

46
00:01:18,812 --> 00:01:20,547
INCLUDING HINGE MOMENTS.

47
00:01:21,047 --> 00:01:22,449
AND FOR THIS COMPARISON,

48
00:01:22,449 --> 00:01:23,983
CFD PRODUCED GOOD,

49
00:01:23,983 --> 00:01:25,919
QUALITATIVE PREDICTIONS.

50
00:01:27,320 --> 00:01:29,089
OF COURSE, THE UNCERTAINTIES

51
00:01:29,089 --> 00:01:30,490
IN BOTH THE EXPERIMENTAL DATA

52
00:01:30,490 --> 00:01:31,825
AND THE CFD RESULTS

53
00:01:31,825 --> 00:01:33,460
NEED TO BE EVALUATED

54
00:01:33,626 --> 00:01:34,861
BEFORE WE CAN DRAW

55
00:01:34,861 --> 00:01:36,062
FIRM CONCLUSIONS ABOUT

56
00:01:36,062 --> 00:01:38,398
THE ACCURACY OF THE SIMULATIONS.

57
00:01:38,965 --> 00:01:40,433
THE CFD PREDICTIONS HAVE

58
00:01:40,433 --> 00:01:42,502
SO FAR BEEN VERY CLOSE

59
00:01:42,502 --> 00:01:44,237
TO THE WIND TUNNEL DATA

60
00:01:44,237 --> 00:01:45,405
AND HAVE HELPED TO UNDERSTAND

61
00:01:45,405 --> 00:01:46,806
THE AERODYNAMIC BEHAVIOR

62
00:01:46,806 --> 00:01:48,541
WE MEASURED IN BETTER DETAIL,

63
00:01:48,541 --> 00:01:49,776
EVEN TRACKING DOWN

64
00:01:49,776 --> 00:01:51,077
SOME INCONSISTENCIES

65
00:01:51,077 --> 00:01:52,946
IN THE EXPERIMENTAL DATA.

66
00:01:54,147 --> 00:01:55,815
WHAT IS STRIKING IS THE FACT

67
00:01:55,815 --> 00:01:57,817
THAT THE EXPERIMENTS IN CFD

68
00:01:57,817 --> 00:01:58,885
HAVE DEFINITE STRENGTHS

69
00:01:58,885 --> 00:02:00,086
AND WEAKNESSES,

70
00:02:00,086 --> 00:02:01,454
AND COMBINING THEM LETS US

71
00:02:01,454 --> 00:02:02,522
UNDERSTAND MORE ABOUT

72
00:02:02,522 --> 00:02:03,556
THE COMPLEX FLOWS THAT CAN

73
00:02:03,556 --> 00:02:05,258
HAPPEN IN THE WIND TUNNEL

74
00:02:05,258 --> 00:02:06,359
AND AROUND THE RELATIVELY

75
00:02:06,359 --> 00:02:07,460
SIMPLE VEHICLE SHAPE

76
00:02:07,460 --> 00:02:09,195
WE'VE STUDIED SO FAR.

77
00:02:10,096 --> 00:02:11,364
WE'RE LOOKING FORWARD

78
00:02:11,364 --> 00:02:12,465
TO STUDYING SEVERAL

79
00:02:12,465 --> 00:02:13,733
MORE COMPLICATED FLOWS

80
00:02:13,733 --> 00:02:15,768
IN THE NEAR FUTURE.