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AD-A243 265 TECHCAL REPORT BRL-TR-3300 ... D T IC _ _ __ I Bi IhL DECi I 1991 GUN TUBE HEATING PAUL J. CONROY DECEMBER 1991 APPROV rFOR PBuC R ,LEASED; mUTION IS UNLahIunD. 0.Ma U.S. ARMY LABORATORY COMMAND BALLISTIC RESEARCH LABORATORY ABERDEEN PROVING GROUND, MARYLAND i2 29-05-7- NOTICES Destroy this report when it is no longer needed. DO NOT return it to the originator. Additional copies of this report may be obtained from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161. The findings of this report are not to be construed as an official Department of the Army position, unless so designated by other authorized documents. The use of trade names or manufacturers' names in this report does not constitute indorsement of any -commercial product. -UNCLASSIFIED-_ _ _ _ _ _ _ REPORT DOCUMENT PAGE ~ai ~3s -~w~ . 19~9U 1I~mm1 a* 16.16.909 1W~Wq 1..~ ;1wipm-. . f =8118 -- fte .ON" dIONMR .- seft"M ogf ebwdloma -a. bohift ftue was.ao wZ. ..aaif *gt0Wu ,t Edd..d wu8.gIY1j.0.dmii 8e-6w" 31.69.0. . D9b6w.1 ain" if bfialemmi@ 6.109. .9a."a a waleyf.tE,. 1 142u16,w *W JnM~ 3eE.U0b dd. DOW$d.9 .wm. 0"4 120$ AUrg0e..-VA 222L4OU. ow ble On01 4 0. Umosagmaa, d %.ft.a pe.Afb.at1dO04S. wlgs.D26 aL"aV* 1. AGENCY USE ONLY hienki 2.- REMYR DATE 3.* REPORTTP N AE OEE I December 199j Final, Feb 90 - Dec 90 * 4. TILE AN SUTTS . FUNDING NURBERS * ~~~Gun Tube HeatingPR L610A4 S.AUTHOR(S) Paul J. Conroy 7. PERFORMING ORGANIZATION NAME(S) AND A-DDRFESSIES) 8. PERFORMING ORGANIZATION REPORT NUMBER S.-SPONSORINGIMONITORING AGMNCY NAMES(S) AND ADORESSIES) I 0.SPONSRING/MONITORt4 AGENCY REPORT NUMBER USA Ballistic Research Labo~ratory ATTN: SLCBR-DD-T BLT-3 Aberdeen Proving Ground. MD 21005-5066 11. SUPPLEMENTARY NOTES 1 12a. DISTRIBUTION/iVAILABILITY STATEMENT 2b. DISTRIBUTiON CODE Approved for Public Release - Distribution is UnlimitedJ 13. ABSTRACT Afazmwm 200 woods) A one-dimensional gun tube heating model has been coupled to an interior ballistic code. The ballistic code models the two-phase interior ballistic cycle and provides intensive and extensive properties throughout the cycle. At the inner wall of the gun tube, a turbulent boundary layer correlation is used to compute the heat flux to the wall. This correlation incorporates the compressibility of the flow in calculating the Reynolds number and skin friction coefficient. Within the tube wall, the one-dimensional radial heat conduction equation is solved. The model is used to investigate gun tube thermal profiles over multiple firings with variable firing rates for two different weapons. Results are used to describe the transient heating of the gun tube over a long period of continuous firin g. Potential firing scenarios are presented and discussed. Numerical results are compared to experimental work performed in the past. An extensive reference list is also includedl. 14. SBJECTTERMS15; NUMBE-OF PAGES interior ballistics, barrel heating, heat transfer, heat counduction, thermal maaemn 32 1.PIECODE- 17 ECV lA1.S KIASCMU NTY CIASSMAATIO#4 11. SEUT I CATION 20. UMIATMO OP -A&STRCT - OF REW OF TMI PAOE OF *3mwPA UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED SAR NSN 754".1- 2M05500 UNCLASSIFIED w d -29 f184 ptemibal by ANStWm 231 233.102 -__ = INTENTIONALLY LEFT B-LA(cid:127)NK. TABLE.OF CONTENTS LIST OF FIGURES ........................................... v- ACKNOWLEDGMENTS ........................................ vii 1. INTRODUCTION ............................................. 1 2. ANALYTICAL DESCRIPTION .................................... 2 3. NUMERICAL CALCULATIONS ................................... 7 4. DISCUSSION ............................................... 7 5. CONCLUSIONS .............................................. 13 6. CODE IMPROVEMENTS UNDER IMPLEMENTATION OR CONSIDERATION ...................................... 13 7. REFERENCES .............................................. 15 LIST OF SYMBOLS ........... .............................. 19 LIST OF ABBREVIATIONS ...................................... 21 DISTRIBUTION LIST .......................................... 23 Acoossio(cid:127) For NTIS GRA&I DIMC T" I SDistribatlon/_ - D-i3,ii1 a,,/or Dia INTENTIONALLY LEFT BLANK. iv LIST OF FIGURES Figur~e Fage 1. Heat Transfer Code Flow Chart .................................. 6 2. Numerical Gun Tube Tempetature Calculation Results at Both the Inner and Outer Walls for the M203 Charge in a 155-mm Howitzer at the Origin of Rifling for S Rounds Per Minute for 3 Minutes Followed by 3 Rounds Per Minute Continuous ..................... 8 3. Experimental vs. Numerical Results for the Outer Gun Tube Temperature at the Origin of Rifling for the M203 Charge in a 155-mm Howitzer, Given the Firing Rate in Figure 2 .............. 8 4. Numerical Gun Tube Temperature Calculation Results at Both the Inner and Outer Walls for the M203 Charge in a 155-mm Howitzer at the Origin of Rifling for 6 Rounds Per Minute for 5 Minutes Followed by 3 Rounds Per Minute Continuous ..................... 9 5. Numerical Gun 1 ube Temperature Calculation Results at Both the Inner and Outer Wails for the M203 Charge in a 155-mm Howitzer at the Origin of Rifling for 12 Rounds Per Minute for 5 Minutes Followed by 3 Rounds Per Minute Continuous ..................... 9 6. A Comparison of Wall Temperature Profiles for the 12 Rounds Per Minute vs. the 6 Rounds Per Minute Scenarios After 30 Rounds and 6 Rounds Per Minute After 18 Rounds ....................... 10 7. Experimental Lccation of the Thermocouples for the 27-mm CAW Study ..... 12 8. Typ:cal Experimental Thermocouple Traces for the 27-mm CAW Study 0.000254 m (0.01 in.) From the Inner Wall ........................ 12 9. Numerical Results for the 27-mm CAW Study at the Stop Shoulder 0.000254 m (0.01 in.) From the inner Wall ........................ 13 v INTENTIONALLY I EFT BLANK. vi ACKNOWLEDGMENTS I wish to thank Dr. George Keller and Mr. Albert Horst for providing me the atmosphere, tools, and time to do this work. Also, I would like to express my appreciation to Satish Chandra of Veritay Corporation for many discussions on the heat conduction code and Hugh McEiroy and his group at Olin Corporation for the deterred ball propellant chemical data. vii INTENTVONALLY LEFT BLANK. viii