محاسبه تضعیف در محیط باران با مدل‌سازی شکل واقعی قطرات به روش تفاضل محدود حوزه زمان

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشگاه صنعتی نوشیروانی بابل

2 صنعتی نوشیروانی

3 دانشکده مهندسی برق و کامپیوتر، دانشگاه صنعتی نوشیروانی بابل

چکیده

روش تفاضل محدود در حوزه زمان در سه بعد پیاده‌سازی و از آن برای محاسبه سطح مقطع کل ناشی از قطرات باران با شکل واقعی استفاده شده است. راستی‌آزمایی نتایج این روش از طریق شبیه‌سازی مدل MPP (واقعی) قطره باران با استفاده از روش معادلات انتگرالی حجمی در نرم‌افزار CST مورد بررسی قرار گرفته است. همچنین میزان دقت مدل بیضی‌گون‌ قطره باران از طریق مقایسه نتایج سطح مقطع کل آن با مدل MPP سنجیده و نتایج شبیه‌سازی‌ها در فرکانس GHz 30 و به‌ازای قطبش‌های عمودی و افقی موج تابشی ارائه شده است. در نهایت از نتایج محاسبات سطح مقطع کل برای محاسبه تضعیف ویژه قطرات باران با مدل توزیع مارشال- پالمر برای قطرات در محیط استفاده شده است. نمودارهای میزان تضعیف ویژه ناشی از محیط باران به ازای شدت بارش‌های مختلف و در قطبش‌های عمودی و افقی موج تابشی ارائه شده‌اند. این نتایج در محاسبات مربوط به انتشار امواج در محیط‌های بارانی قابل اعمال خواهند بود.

کلیدواژه‌ها


عنوان مقاله [English]

Calculation of Attenuation in Rain Medium with Realistic Rain drops Shapes Modeling by the FDTD Method

نویسندگان [English]

  • F. Damavandi Kamali 1
  • A. Ebrahimzadeh 2
  • M. Yazdi 3
1 Babol Noshirvani University of Technology
2 Babol Noshirvani University of Technology
3 Babol Noshirvani University of Technology
چکیده [English]

Total cross section (TCS) of rain drops with realistic shape model (Modified Pruppacher Pitter or MPP model) is calculated by Finite difference time domain (FDTD) method implemented in three dimensions. FDTD Results are validated by the volume integral equation (VIE) method through simulation of rain drop model in commercial software CST Microwave Design Studio. The accuracy of oblate spheroidal model as a simpler model for rain drops is also compared with MPP model results. Simulation are performed at the frequency of 30 GHz, in both vertical and horizontal polarizations of incident wave. TCS results are then used for the calculation of rain specific attenuation with Marshal-Palmer (M-P) rain drop size distribution (DSD). The specific attenuation of spheroidal and MPP rain drops models are calculated and compared for different rain rates in vertical and horizontal polarizations of incident wave. These results can be applied for applications with wave propagation in rainy mediums.

کلیدواژه‌ها [English]

  • FDTD
  • TCS
  • MPP rain drop model
  • specific attenuation
  • DSD
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