Recent applications of CFD to the aerodynamics of army projectiles at the U.S. Army Ballistic Research Laboratory

Sturek, Walter B.; Nietubicz, Charles J.

doi:10.2514/6.1992-4349

Cited by 10 publications

(15 citation statements)

References 8 publications

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“…Again, only M 1 D 4:4 data were given in Ref. 7. Notice the good agreement of the AP02 to the CFD computations.…”

Section: Pitch Damping Of Flared Con Gurationsmentioning

confidence: 95%

Semiempirical Prediction of Pitch Damping Moments for Configurations with Flares

Moore¹,

Hymer

2001

Journal of Spacecraft and Rockets

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New capability has been added to the Naval Surface Warfare Center aeroprediction code to allow aerodynamics to be predicted for Mach numbers up to 20 for con gurations with ares. This new capability includes extending the static aerodynamic predictions for Mach numbers less than 1.2, improving the body alone pitch damping for Mach numbers above 2.0, and developing a new capability for pitch damping of ared con gurations at Mach numbers up to 20. This new capability for ared con gurations was validated for several different con gurations in the Mach number range of 2-8.8. Whereas ared con guration aerodynamics have been validated only up to Mach 8.8, static aerodynamics have been validated in previous references for other con gurations as high as Mach number 14. Most validations of the aeroprediction code have been performed between Mach numbers of 0.1 and 5, where most experimental data are available. In general, pitch damping predictions of the improved capability were within 20% of either experimental data or computational uid dynamics calculations. This accuracy level is believed to be quite adequate for dynamic derivatives in the preliminary design stage. These new additions to the aeroprediction code will be transitioned to users as part of the 2002 version of the code (AP02). Nomenclature= reference area (maximum cross-sectional area of body, if a body is present, or planform area of wing, if wing alone), ft 2 C A = axial force coef cient C AB ; C A f ; C AW = base, skin-friction, and wave components, respectively, of axial force coef cient C AF = forebody axial force coef cient .C AF D C A f C C AW / C D = drag coef cient C L = lift coef cient C M = pitching moment coef cient (based on reference area and body diameter, if body present, or mean aerodynamic chord, if wing alone) C Mq C C M P ® = pitch damping moment coef cient [C M .q/=.qd=2V 1 / C C M . P ®/=. P ®d=2V 1 /] C M® = pitching moment coef cient derivative, 1/rad C M .q/ = pitching moment coef cient due to a constant pitching rate of q C M . P ®/ = pitching moment coef cient due to a constant vertical acceleration of P ® C N = normal force coef cient C N® = normal force coef cient derivative, 1/rad d B = body diameter at base, ft d r = reference body diameter, ft ;`n;`a ;`f = body length, nose length, afterbody length, and are length, respectivelỳ 1 = distance from cone apex to are-cylinder juncture M 1 = freestream Mach number

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“…Again, only M 1 D 4:4 data were given in Ref. 7. Notice the good agreement of the AP02 to the CFD computations.…”

Section: Pitch Damping Of Flared Con Gurationsmentioning

confidence: 95%

Semiempirical Prediction of Pitch Damping Moments for Configurations with Flares

Moore¹,

Hymer

2001

Journal of Spacecraft and Rockets

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“…(2)-(5) give the C N and x cp for flares at all Mach numbers. C N is simply followed a fairly smooth pattern, allowing a correction to be derived based on CFD results from R e f s 579 an( j JQ C N f = a (6) for small angles of attack. Since most flare configurations are designed to fly at small angles of attack, Eqs.…”

Section: Static Aerodynamics Of Flared Projectilesmentioning

confidence: 99%

Semiempirical prediction of pitch damping moments for configurations with flares

Moore¹,

Hymer

2001

39th Aerospace Sciences Meeting and Exhibit

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New capability has been added to the NSWC aeroprediction code to allow aerodynamics to be predicted for Mach numbers up to 20 for configurations with flares. This new capability includes extending the static aerodynamic predictions for Mach numbers less than 1.2, improving the body alone pitch damping for Mach numbers above 2.0, and developing a new capability for pitch damping of flared configurations at Mach numbers up to 20.This new capability for flared configurations was validated for several different configurations in the Mach number range of 2 to 8.8. In general, pitch damping predictions of the improved capability was within 20 percent of either experimental data or computational fluid dynamics calculations. This accuracy level is believed to be quite adequate for dynamic derivatives in the preliminary design stage. These new additions to the aeroprediction code will be transitioned to users as part of the 2002 version of the code (AP02).

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“…6 This configuration is also a cone-cylinder-flare of 12.28 calibers total length. It has a flare with a 15 deg flare angle that is 2.67 calibers in length.…”

Section: Pitch Damping Of Flared Configurationsmentioning

confidence: 99%

Improvements in Pitch Damping for the Aeroprediction Code with Particular Emphasis on Flare Configurations

Moore¹,

Hymer²

2000

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, search existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services. NSWCDD/TR-00/009 FOREWORDThe 1998 version of the aeroprediction code (AP98) used an empirical method to compute pitch damping of bodies alone. This method was based on a 1970's version of a model developed by Bob Whyte of General Electric (GE) (Bob has since left GE and formed his own company). The method was a data base that used aerodynamics of Army and Navy spin stabilized shells as a means to estimate aerodynamics of other configurations. The Whyte code (referred to as the "GE Spinner" code) worked well for configurations that had Mach numbers less than about 3.0. However, for many missile configurations at high Mach numbers, or configurations that used flares for stability, the GE Spinner code gives erroneous answers, since it was not developed with those conditions in mind. The work presented in this report develops new semiempirical technology to address the weak areas of the GE Spinner code for the pitch damping coefficient.

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Recent applications of CFD to the aerodynamics of army projectiles at the U.S. Army Ballistic Research Laboratory

Cited by 10 publications

References 8 publications

Semiempirical Prediction of Pitch Damping Moments for Configurations with Flares

Semiempirical Prediction of Pitch Damping Moments for Configurations with Flares

Semiempirical prediction of pitch damping moments for configurations with flares

Improvements in Pitch Damping for the Aeroprediction Code with Particular Emphasis on Flare Configurations

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