شبیه‌سازی موج انفجار ضربه‌ای دهانه سلاح در فواصل مختلف

چکیده

اغلب تسلیحات پس از شلیک، یک موج انفجاری از دهانه خارج شده و با سرعت و فشار زیاد در هوا منتشر می گردد و در نهایت به سازه اطراف آن برخورد می کند. در تسلیحات سنگین با فرکانس بالای شلیک، ضربات متداول موج باعث ایجاد ارتعاش شدید به سازه و تجهیزات می شود. از طرفی این امواج بر روی انسان تاثیر سوء و در نتیجه کاهش کارکرد خدمه را در پی خواهد داشت. در این مقاله با استفاده از روش مقیاس سازی، مدلی از موج انفجار ارائه و با استفاده از شکل موج فریدلندر برای بیان رفتار موج، مشخصات آن تخمین زده شد. برای تعریف موج انفجار از سه پارامتر زمان رسیدن موج از نقطه ی مورد نظر، فشار حداکثر و زمان ماندگاری در فاز مثبت، استفاده می‌شود. در مورد زمان رسیدن از رابطه ی نیمه تجربی استفاده شده است. برای محاسبه‌ی فشار برگشتی موج از سازه در زوایای کوچک از تئوری شوک مورب و در زوایای بزرگتر از روش تجربی همراه با میان یابی لاگرانژی استفاده شده است. روابط برای دو حالت فاصله ی از 10تا 50 و50 تا 400 برابر قطر لوله بدست خواهد آمد و با نتایج آزمایشگاهی سلاحی با کالیبر 30 و تانکی با کالیبر 105 میلی متری مقایسه می‌گردد. نتایج در مورد زمان رسیدن و فشار برگشتی بسیار مناسب و درباره زمان ماندگاری در فاز مثبت خطا نسبت به مقاله مرجع خطای کمتری دارد.

کلیدواژه‌ها


عنوان مقاله [English]

Simulation of Gun Muzzle Blast Wave in Different Distances

چکیده [English]

Almost every guns produce high speed and great pressure muzzle blast when they start to shoot. They also damage surrounded structures in their vicinity. In heavy weapons with high frequency of firing, the structure around the gun is incurred under the regular impacts of blast waves. On the other hand, these waves can also negatively impress crews, so their efficiency would be reduced. In this paper, a model of muzzle blast is revealed with the aid of scaling approach, and the traits are estimated with the aid of Friedlander wave form. Blast arrival time, maximum pressure, and positive phase duration are used to describe the muzzle blast. In the case of arrival time, Semi-experimental methods are also utilized. Solution of the reflected pressure at low angles has done with the Oblique Shock Theory, and at the bigger angles experimental methods along with Lagrangian Interpolation is utilized. The equations are attained within two ranges of distances. First: 10 to 50 times of barrel diameter, second is 50 to 400 times of the barrel diameter. The results are also validated with the experimental data from a30 mmcaliber gun and a105 mmcaliber tank. Results of arrival time and reflected pressure are appropriately efficient, and Positive Time Duration although shows a little more error from the experimental error, has half error in compare with the last theory. Almost every guns produce high speed and great pressure muzzle blast when they start to shoot. They also damage surrounded structures in their vicinity. In heavy weapons with high frequency of firing, the structure around the gun is incurred under the regular impacts of blast waves. On the other hand, these waves can also negatively impress crews, so their efficiency would be reduced. In this paper, a model of muzzle blast is revealed with the aid of scaling approach, and the traits are estimated with the aid of Friedlander wave form. Blast arrival time, maximum pressure, and positive phase duration are used to describe the muzzle blast. In the case of arrival time, Semi-experimental methods are also utilized. Solution of the reflected pressure at low angles has done with the Oblique Shock Theory, and at the bigger angles experimental methods along with Lagrangian Interpolation is utilized. The equations are attained within two ranges of distances. First: 10 to 50 times of barrel diameter, second is 50 to 400 times of the barrel diameter. The results are also validated with the experimental data from a30 mmcaliber gun and a105 mmcaliber tank. Results of arrival time and reflected pressure are appropriately efficient, and Positive Time Duration although shows a little more error from the experimental error, has half error in compare with the last theory. Almost every guns produce high speed and great pressure muzzle blast when they start to shoot. They also damage surrounded structures in their vicinity. In heavy weapons with high frequency of firing, the structure around the gun is incurred under the regular impacts of blast waves. On the other hand, these waves can also negatively impress crews, so their efficiency would be reduced. In this paper, a model of muzzle blast is revealed with the aid of scaling approach, and the traits are estimated with the aid of Friedlander wave form. Blast arrival time, maximum pressure, and positive phase duration are used to describe the muzzle blast. In the case of arrival time, Semi-experimental methods are also utilized. Solution of the reflected pressure at low angles has done with the Oblique Shock Theory, and at the bigger angles experimental methods along with Lagrangian Interpolation is utilized. The equations are attained within two ranges of distances. First: 10 to 50 times of barrel diameter, second is 50 to 400 times of the barrel diameter. The results are also validated with the experimental data from a30 mmcaliber gun and a105 mmcaliber tank. Results of arrival time and reflected pressure are appropriately efficient, and Positive Time Duration although shows a little more error from the experimental error, has half error in compare with the last theory. Almost every guns produce high speed and great pressure muzzle blast when they start to shoot. They also damage surrounded structures in their vicinity. In heavy weapons with high frequency of firing, the structure around the gun is incurred under the regular impacts of blast waves. On the other hand, these waves can also negatively impress crews, so their efficiency would be reduced. In this paper, a model of muzzle blast is revealed with the aid of scaling approach, and the traits are estimated with the aid of Friedlander wave form. Blast arrival time, maximum pressure, and positive phase duration are used to describe the muzzle blast. In the case of arrival time, Semi-experimental methods are also utilized. Solution of the reflected pressure at low angles has done with the Oblique Shock Theory, and at the bigger angles experimental methods along with Lagrangian Interpolation is utilized. The equations are attained within two ranges of distances. First: 10 to 50 times of barrel diameter, second is 50 to 400 times of the barrel diameter. The results are also validated with the experimental data from a30 mmcaliber gun and a105 mmcaliber tank. Results of arrival time and reflected pressure are appropriately efficient, and Positive Time Duration although shows a little more error from the experimental error, has half error in compare with the last theory.

کلیدواژه‌ها [English]

  • Muzzle Blast Wave
  • Arrival time
  • Positive Time Duration
  • Peak Overpressure
  • Reflected Pressure
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[3]          Heaps, C. W., Fansler, K. S., and Schmidt, E. M., “Computer Implementation of a Muzzle Blast Prediction Technique,” The Shock and Vibration Bulletin, Naval Research Laboratory, Washington, DC, Bulletin 56, 1986, p. 213-229.

[4]          J. Kitzman, K. S. Fansler, W. G. Thompson, "Muzzle Blast From 105mm M735 Round", US Army Research Laboratory, 1992,  AD-A245 565

[5]          K.S. Fansler, " Description of Gun Muzzle Blast by Modified Ideal Scaling Models", Army Research Laboratory, 1997,  ARL-TR-1434

[6]          D.L. Cler, N. Chevaugeon, " Computational fluid dynamics application to gun muzzle blast a validation case study", U. S. Army Armament Research ,2003, ARCCB-TR-03011

[7]          Dae-Kwan Kim, Jae-Hung Han, " Establishment of Gun Blast Wave Model and Structural Analysis for Blast Load", AIAA Journal, 2006

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[9]         محمد حسین صادقی، محمدرضا خدمتی، مهدی فکوری، محمد رضایی سنگتابی "تحلیل اجزای محدود عرشه شناورهای آلومینیومی تحت اثر فشار موج ناشی از شلیک سلاح"، دوازدهمین همایش صنایع دریایی، 1389

[10]     محمدرضا خدمتی، محمد حسین صادقی، ”بررسی روشهای مختلف شبیه‌سازی و تخمین بارهای ضربه‌ای انفجاری موثر بر سازه‌ها“، دهمین همایش صنایع دریایی. 1387.