Mobile QR Code QR CODE : Journal of the Korean Society of Civil Engineers

  1. *์ธ์ฒœ๋Œ€ํ•™๊ต ์•ˆ์ „๊ณตํ•™๊ณผ ์กฐ๊ต์ˆ˜ ()
  2. **์„œ์šธ๋Œ€ํ•™๊ต ๊ฑด์„คํ™˜๊ฒฝ๊ณตํ•™๋ถ€ ๊ต์ˆ˜ (**Seoul National University)
  3. ***(์ฃผ)์›น์†”๋ฃจ์Šค ์ „๋ฌด ()
  4. ****์„œ์šธํ•™๊ต ๊ฑด์„คํ™˜๊ฒฝ๊ณตํ•™๋ถ€ ๋ฐ•์‚ฌ ํ›„ ์—ฐ๊ตฌ์› ()


๊ณก์„ ์ˆ˜๋กœ, ์ด์ฐจ๋ฅ˜, ์œ ์† ๋ถ„ํฌ, ๋ถ„์‚ฐ์‘๋ ฅ๋ฒ•, ์ฒœ์ˆ˜๋ฐฉ์ •์‹, ์œ ํ•œ์š”์†Œ๋ชจํ˜•
Curved channel, Secondary current, Velocity profile, Dispersion stresses method, Shallow water equations, Finite element model

  • 1. ์„œ ๋ก 

  • 2. ์ด๋ก ์  ์—ฐ๊ตฌ

  •   2.1 ์ด์ฐจ๋ฅ˜ ์œ ์†๋ถ„ํฌ

  •   2.2 ์ด์ฐจ๋ฅ˜ ์˜ํ–ฅ ํ•ด์„ ๋ฐฉ๋ฒ•

  • 3. ๋ถ„์‚ฐ์‘๋ ฅ ๋ชจํ˜•

  • 4. ์ˆ˜์น˜๋ชจ์˜

  •   4.1 30๋„ ๊ณก์„ ์ˆ˜๋กœ

  •   4.2 90๋„ ๊ณก์„ ์ˆ˜๋กœ

  •   4.3 270๋„ ๊ณก์„ ์ˆ˜๋กœ

  • 5. ๊ฒฐ ๋ก 

1. ์„œ ๋ก 

์ž์—ฐํ•˜์ฒœ์˜ ๋งŒ๊ณก๋ถ€์—์„œ๋Š” ์›์‹ฌ๋ ฅ, ํšก๋ฐฉํ–ฅ ์ˆ˜๋ฉด๊ฒฝ์‚ฌ์— ์˜ํ•œ ์••๋ ฅ์ฐจ, ๋‚œ๋ฅ˜์— ์˜ํ•œ ์ „๋‹จ๋ ฅ ๋“ฑ์˜ ์ƒํ˜ธ์ž‘์šฉ์œผ๋กœ ์ธํ•ด ์ˆ˜ํ‘œ๋ฉด์—์„œ์˜ ํšก๋ฐฉํ–ฅ ์œ ์†์€ ๊ณก๋ฅ ์˜ ์™ธ์ธก์„ ํ–ฅํ•˜๊ณ , ๋ฐ”๋‹ฅ ๋ถ€๊ทผ์—์„œ์˜ ํšก๋ฐฉํ–ฅ ์œ ์†์€ ๋งŒ๊ณก์˜ ๋‚ด์ธก์„ ํ–ฅํ•˜์—ฌ, ์ฃผ ํ๋ฆ„ ๋ฐฉํ–ฅ์— ์—ฐ์ง์ธ ๋‹จ๋ฉด์„ ๋”ฐ๋ผ Fig. 1๊ณผ ๊ฐ™์€ ๋‚˜์„ ํ˜• ํ๋ฆ„์ธ ์ด์ฐจ๋ฅ˜๊ฐ€ ๋ฐœ์ƒํ•œ๋‹ค. Tominaga์™€ Nezu(1991)๋Š” ํ•˜์ฒœ ์ง์„ ๊ตฌ๊ฐ„ ๋‚ด์—์„œ์˜ ์ด์ฐจ๋ฅ˜๋Š” ์ข…๋ฐฉํ–ฅ ์œ ์†์˜ ์ตœ๋Œ€ 4% ์ •๋„์˜ ํฌ๊ธฐ๋ฅผ ๊ฐ€์ง„๋‹ค๊ณ  ์ œ์‹œํ•˜์˜€๊ณ , Shiono์™€ Muto(1998)๋Š” ์‚ฌํ–‰ํ•˜์ฒœ ๋‚ด์—์„œ์˜ ์ข…๋ฐฉํ–ฅ ์œ ์†๊ณผ ๋น„๊ตํ•˜์—ฌ ์ด์ฐจ๋ฅ˜์˜ ํฌ๊ธฐ๊ฐ€ ๋Œ€๋žต 10-16% ์ •๋„์˜ ๊ฐ’์„ ๊ฐ–๋Š”๋‹ค๊ณ  ์ฃผ์žฅํ•˜์˜€๋‹ค. ์ด์™€ ๊ฐ™์ด ์ด์ฐจ๋ฅ˜๋Š” ์ฃผ ํ๋ฆ„์— ๋น„ํ•ด ๊ทธ ํฌ๊ธฐ๊ฐ€ ์ž‘์ง€๋งŒ ์ฃผ ํ๋ฆ„ ์œ ์† ๊ตฌ์กฐ๋ฅผ ๋ณ€ํ™”์‹œํ‚ค๋ฉฐ ์œ ์‚ฌ ์ด์†ก, ํ•˜์ƒ ๋ฐ ์ œ๋ฐฉ ์นจ์‹, ํ•˜์ƒ ์ง€ํ˜• ๋ณ€ํ™” ๋“ฑ์— ํฐ ์˜ํ–ฅ์„ ๋ฏธ์นœ๋‹ค. ๋˜ํ•œ ์˜ค์—ผํ™•์‚ฐ์˜ ๊ฒฝ์šฐ ํ•˜ํญ๋ฐฉํ–ฅ์œผ๋กœ ์™„์ „ํžˆ ํ˜ผํ•ฉ๋˜๊ธฐ ์ „๊นŒ์ง€์˜ ๋ถ„์‚ฐ๊ณผ์ •์—์„œ ์ด์ฐจ๋ฅ˜๊ฐ€ ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์€ ๋งค์šฐ ์ค‘์š”ํ•˜๋‹ค.

๊ธฐ์กด ๋Œ€๋ถ€๋ถ„์˜ ์ฒœ์ˆ˜ํ๋ฆ„ ํ•ด์„๋ชจํ˜•์—์„œ๋Š” ์—ฐ์ง๋ฐฉํ–ฅ์œผ๋กœ ๊ท ์ผํ•œ ์œ ์†์„ ๊ฐ€์ •ํ•˜์˜€๊ธฐ ๋•Œ๋ฌธ์— ํ•˜์ฒœ ๋งŒ๊ณก๋ถ€์—์„œ ์ด์ฐจ๋ฅ˜์˜ ์˜ํ–ฅ์„ ๊ณ ๋ คํ•˜์ง€ ๋ชปํ•˜๊ณ  ๋ถ€์ •ํ™•ํ•œ ํ๋ฆ„ํ•ด์„ ๊ฒฐ๊ณผ๋ฅผ ๋„์ถœํ•˜์˜€๋‹ค. ๋”ฐ๋ผ์„œ ๊ธฐ์กด์˜ ๋ชจํ˜•์—์„œ๋Š” ๋ฌผ๋ฆฌ์ ์œผ๋กœ ์™œ๊ณก๋œ ๋‚œ๋ฅ˜ ๋™์ ์„ฑ๊ณ„์ˆ˜๋ฅผ ์ž…๋ ฅํ•˜์—ฌ ๊ณก์„ ๋ถ€์—์„œ์˜ ์œ ์†๊ตฌ์กฐ๋ฅผ ๋งž์ถ”๋ ค๋Š” ์‹œ๋„๊ฐ€ ๋นˆ๋ฒˆํ•˜์˜€๋‹ค. ๋˜ํ•œ ์ •๊ตํ•œ ๋‚œ๋ฅ˜๋ชจํ˜•์„ ์ด์šฉํ•˜์—ฌ ๋ ˆ์ด๋†€์ฆˆ ์‘๋ ฅ์„ ๊ณ„์‚ฐํ•˜์˜€์ง€๋งŒ ์ด์ฐจ๋ฅ˜์˜ ํšจ๊ณผ๋ฅผ ๋ฐ˜์˜ํ•˜์ง€ ์•Š์•„ ๋งŒ๊ณก๋ถ€์—์„œ์˜ ์‹ค์ œ ์œ ์†์„ ์˜ฌ๋ฐ”๋ฅด๊ฒŒ ๋ชจ์˜ํ•˜์ง€ ๋ชปํ•˜๋Š” 2์ฐจ์› ๋ชจํ˜•๋„ ๋‹ค์ˆ˜ ์กด์žฌํ•œ๋‹ค(Ye์™€ McCorquodale, 1997; Jia์™€ Wang, 1998; Wilson ๋“ฑ, 2002).

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” 3์ฐจ์› Reynolds ๋ฐฉ์ •์‹์„ ์ˆ˜์‹ฌ ์ ๋ถ„ํ•˜๋Š” ๊ณผ์ •์—์„œ ๊ท ์ผํ•œ ์œ ์†๋ถ„ํฌ๋ฅผ ๊ฐ€์ •ํ•˜์—ฌ ๋งŒ๊ณก๋ถ€์—์„œ ์ด์ฐจ๋ฅ˜๊ฐ€ ์ฃผ ํ๋ฆ„ ์œ ์†์— ๋ฏธ์น˜๋Š” ์ด์†ก์˜ ์˜ํ–ฅ์„ ๋ฌด์‹œํ•œ ๊ธฐ์กด ๋Œ€๋ถ€๋ถ„์˜ ์—ฐ๊ตฌ์™€๋Š” ๋‹ฌ๋ฆฌ, ์ข…ํšก๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง๋ถ„ํฌ๋ฅผ ํ‰๊ท ๊ฐ’๊ณผ ์ด๋กœ๋ถ€ํ„ฐ์˜ ๋ณ€๋™๋Ÿ‰์œผ๋กœ ๋ถ„ํ• ํ•˜์—ฌ ์ด ๊ฐ’๋“ค์„ ์šด๋™๋Ÿ‰๋ฐฉ์ •์‹์— ๋Œ€์ž…ํ•˜์—ฌ ์ƒ์„ฑ๋˜๋Š” ์ถ”๊ฐ€์ ์ธ ํ•ญ์ธ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•˜๋Š” ์ˆ˜์น˜๋ชจํ˜•์„ ๊ฐœ๋ฐœํ•˜์˜€๋‹ค. ์ œ์•ˆ๋œ ๋ชจํ˜•์„ 30๋„, 90๋„, 270๋„์˜ ๋งŒ๊ณก๋ถ€๋ฅผ ํฌํ•จํ•˜๋Š” ์ˆ˜๋กœ์— ์ ์šฉํ•˜์—ฌ ๋ถ„์‚ฐ์‘๋ ฅ์„ ์ด์šฉํ•œ ๊ณก์„ ์ˆ˜๋กœ์—์„œ์˜ ์ฒœ์ˆ˜ํ๋ฆ„์„ ์ˆ˜์น˜๋ชจ์˜ํ•˜๊ณ  ๋ชจ์˜ ๊ฒฐ๊ณผ๋ฅผ ์ˆ˜๋ฆฌ์‹คํ—˜์— ์˜ํ•œ ์ธก์ •๊ฐ’ ๋ฐ ํƒ€ ๋ชจํ˜•์˜ ๋ชจ์˜ ๊ฐ’๊ณผ ๋น„๊ตํ•˜์˜€๋‹ค.

PIC4D61.jpg

Fig. 1. Velocity Structure for Curved Open-Channel Flow (Song et al., 2012)

2. ์ด๋ก ์  ์—ฐ๊ตฌ

2.1 ์ด์ฐจ๋ฅ˜ ์œ ์†๋ถ„ํฌ

์ด์ฐจ๋ฅ˜ ์œ ์†๋ถ„ํฌ์— ๋Œ€ํ•œ ์ด๋ก ์‹์€ ์—ฌ๋Ÿฌ ์—ฐ๊ตฌ์ž๋“ค์— ์˜ํ•ด ์ œ์‹œ๋˜์—ˆ๋‹ค. Rozovskii(1961)๋Š” ์ฃผ ํ๋ฆ„ ๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง๋ถ„ํฌ๋ฅผ ๋กœ๊ทธํ•จ์ˆ˜๋ฅผ ์ด์šฉํ•˜์—ฌ ์ •์˜ํ•˜๊ณ  ๋งŒ๊ณก๋ถ€์—์„œ ๋‚˜ํƒ€๋‚˜๋Š” ์ด์ฐจ๋ฅ˜์˜ ์™„์ „๋ฐœ๋‹ฌ ํšก๋ฐฉํ–ฅ ์œ ์† ์—ฐ์ง๋ถ„ํฌ์‹์„ ํ•˜์ƒ์˜ ์กฐ๋„์— ๋”ฐ๋ผ ๊ตฌ๋ถ„ํ•˜์—ฌ ์ œ์•ˆํ•˜์˜€๋‹ค. ๋˜ํ•œ ๋งŒ๊ณก๋ถ€์—์„œ ์ฃผ ํ๋ฆ„ ๋ฐฉํ–ฅ ์ด๋™๊ฑฐ๋ฆฌ์— ๋”ฐ๋ผ ์ด์ฐจ๋ฅ˜์˜ ํฌ๊ธฐ๊ฐ€ ์ฆ๊ฐ€ ๋ฐ ๊ฐ์†Œํ•˜๋Š” ๊ฒฝํ–ฅ์„ ์ง€์ˆ˜ํ•จ์ˆ˜๋ฅผ ์ด์šฉํ•˜์—ฌ ๋‚˜ํƒ€๋ƒˆ๋‹ค. Kikkawa ๋“ฑ(1976)์€ ์ˆ˜์‹ฌ ํ‰๊ท ํ•œ ๋‚œ๋ฅ˜ ๋™์ ์„ฑ ๊ณ„์ˆ˜๋ฅผ ์ ์šฉํ•˜์—ฌ ๊ณ„์‚ฐํ•˜๊ธฐ ์‰ฌ์šด ํ˜•ํƒœ์˜ ํšก๋ฐฉํ–ฅ ์œ ์† ๋ถ„ํฌ์‹์„ ์ œ์•ˆํ•˜์˜€๊ณ , de Vriend(1977)๋Š” ์ด์ฐจ๋ฅ˜์˜ 3์ฐจ์›์  ์˜ํ–ฅ์„ ์ฒœ์ˆ˜ํ๋ฆ„ ํ•ด์„ ๋ชจํ˜•์œผ๋กœ ๊ธฐ์ˆ ํ•˜๊ธฐ ์œ„ํ•œ ์ˆ˜์น˜๋ชจํ˜•์„ ๊ฐœ๋ฐœํ•˜์—ฌ, ์ฃผ ํ๋ฆ„๊ณผ ์ƒํ˜ธ์ž‘์šฉํ•˜๋Š” ์ด์ฐจ๋ฅ˜์˜ ์œ ์†๊ตฌ์กฐ์— ๋Œ€ํ•œ ๋ชจํ˜•์„ ์ œ์•ˆํ•˜์˜€๋‹ค. Odgaard(1986)๋Š” ๋ฉฑํ•จ์ˆ˜๋ฅผ ์ด์šฉํ•˜์—ฌ ์ฃผ ํ๋ฆ„ ๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง๋ถ„ํฌ๋ฅผ ๋‚˜ํƒ€๋ƒˆ์œผ๋ฉฐ, ๋งŒ๊ณก๋ถ€์—์„œ ํ˜•์„ฑ๋˜๋Š” ์ด์ฐจ๋ฅ˜ ์…€ ์ค‘์‹ฌ์—์„œ๋ถ€ํ„ฐ ๋ฐœ์ƒํ•˜๋Š” ์›์‹ฌ๋ ฅ์„ ๊ณ ๋ คํ•˜์—ฌ, ์—ฐ์ง๋ฐฉํ–ฅ์„ ๋”ฐ๋ผ ์„ ํ˜•์ ์œผ๋กœ ๋ณ€ํ™”ํ•˜๋Š” ํšก๋ฐฉํ–ฅ์œ ์† ๋ถ„ํฌ๋ฅผ ์ œ์•ˆํ•˜์˜€๋‹ค.

Rozovskii(1961)๊ฐ€ ์ œ์•ˆํ•œ ์‹์€ ํ•ด์„์ ์œผ๋กœ ์ ๋ถ„ํ•˜๊ธฐ ์–ด๋ ค์šด ํ˜•ํƒœ์˜ ํ•จ์ˆ˜๋ฅผ ํฌํ•จํ•˜๋ฉฐ, Kikkawa ๋“ฑ(1976)์ด ์ œ์•ˆํ•œ ์‹์„ ์‹คํ—˜์ˆ˜๋กœ์—์„œ ์ธก์ •ํ•œ ์œ ์†์ž๋ฃŒ์™€ ๋น„๊ตํ•ด ๋ณด๋ฉด ํšก๋ฐฉํ–ฅ ์œ ์†์˜ ํฌ๊ธฐ๋ฅผ ๊ณผ๋Œ€ ์‚ฐ์ •ํ•˜๋Š” ๊ฒฝํ–ฅ์„ ๋ณด์ด๊ณ  ์žˆ์œผ๋ฉฐ, ์œ ๋„๊ณผ์ •์— ์žˆ์–ด์„œ ๊ฒฝ๊ณ„์กฐ๊ฑด์— ๋Œ€ํ•œ ๋งŽ์€ ๊ฐ€์ •์„ ํฌํ•จํ•˜๊ณ  ์žˆ๊ณ  ์‹ค์ œ ์ž์—ฐํ•˜์ฒœ์˜ ๋ณต์žกํ•œ ์ง€ํ˜•์— ์ ์šฉํ•˜๋Š”๋ฐ ํ•œ๊ณ„๊ฐ€ ์กด์žฌํ•œ๋‹ค. ์ด์ฐจ๋ฅ˜์˜ ์œ ์†๊ตฌ์กฐ์— ๋Œ€ํ•œ Odgaard (1986)์˜ ์ œ์•ˆ์‹์€ ํ•˜์ƒ ์กฐ๋„์˜ ์˜ํ–ฅ์œผ๋กœ ๋ณต์žกํ•˜๊ฒŒ ๋‚˜ํƒ€๋‚˜๋Š” ํšก๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง๋ถ„ํฌ๋ฅผ ๋‚˜ํƒ€๋‚ด์ง€ ๋ชปํ•˜๋ฉฐ, ๋ฐ”๋‹ฅ๋ฉด์—์„œ์˜ ๋ฌดํ™œ(no-slip condition)์„ ๋งŒ์กฑํ•˜์ง€ ์•Š๋Š” ํ•œ๊ณ„์ ์„ ์ง€๋‹ˆ๊ณ  ์žˆ๋‹ค.

2.2 ์ด์ฐจ๋ฅ˜ ์˜ํ–ฅ ํ•ด์„ ๋ฐฉ๋ฒ•

๋งŒ๊ณก๋ถ€์—์„œ์˜ ์ด์ฐจ๋ฅ˜ ์œ ์† ๊ตฌ์กฐ๋ฅผ ์ฒœ์ˆ˜ ํ๋ฆ„ ํ•ด์„์— ๋ฐ˜์˜ํ•˜๊ธฐ ์œ„ํ•˜์—ฌ ๋‘ ๊ฐ€์ง€ ๋ฐฉ๋ฒ•์ด ๋„๋ฆฌ ์‚ฌ์šฉ๋˜๊ณ  ์žˆ๋‹ค. ์ฒซ ๋ฒˆ์งธ ๋ฐฉ๋ฒ•์€ VAM (2D Vertically Averaged and Moment) ๋ชจ๋ธ์— ์˜ํ•œ ๋ฐฉ๋ฒ•(Ghamry, 1999; Ghamry์™€ Steffler, 2002; Ghamry์™€ Steffler, 2005; Vasquez ๋“ฑ, 2006)์ด๊ณ , ๋‘ ๋ฒˆ์งธ ๋ฐฉ๋ฒ•์€ ๋ณธ ์—ฐ๊ตฌ์—์„œ ์ด์šฉํ•œ ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์„ ํฌํ•จํ•˜๋Š” ๋ฐฉ๋ฒ•(de Vriend, 1977)์ด๋‹ค. VAM ๋ฐฉ๋ฒ•์€ Fig. 2์™€ ๊ฐ™์ด x, y, z๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง ๋ถ„ํฌ์™€ ์••๋ ฅ ๋ถ„ํฌ๋ฅผ ๋‹จ์ˆœํ•œ ์„ ํ˜• ํ˜•ํƒœ๋กœ ๊ฐ€์ •ํ•˜์—ฌ ์ด ๊ฐ๊ฐ์˜ ๋ถ„ํฌ๋ฅผ ์ถ”๊ฐ€์ ์ธ ๋งค๊ฐœ๋ณ€์ˆ˜(moments)๋ฅผ ์ด์šฉํ•˜์—ฌ ๋ชจ๋ธ๋งํ•˜๋Š” ๊ธฐ๋ฒ•์ด๋‹ค. ๋”ฐ๋ผ์„œ ์ด ๋ฐฉ๋ฒ•์€ ์‹ (1)๊ณผ ๊ฐ™์€ ์ˆ˜์‹ฌ ํ‰๊ท ๋œ ์—ฐ์†๋ฐฉ์ •์‹, ์‹ (2)์˜ ์šด๋™๋Ÿ‰๋ฐฉ์ •์‹๊ณผ ๋”๋ถˆ์–ด ์‹ (3)์˜ ์šด๋™๋Ÿ‰๋ฐฉ์ •์‹์— ์—ฐ์ง๋ฐฉํ–ฅ ๋ณ€์ˆ˜๋ฅผ ๊ณฑํ•˜์—ฌ ์ถ”๊ฐ€์ ์œผ๋กœ ์ƒ์„ฑ๋˜๋Š” ์šด๋™๋Ÿ‰ ๋ชจ๋ฉ˜ํŠธ ๋ฐฉ์ •์‹(moment of momentum equations)์„ ์—ฐ๊ณ„ ํ•ด์„ํ•˜์—ฌ ์ด์ฐจ๋ฅ˜ ์œ ์†๊ตฌ์กฐ๋ฅผ ๋ฐ˜์˜ํ•˜๋Š” ๋ฐฉ๋ฒ•์ด๋‹ค.

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Fig. 2. Linear Vertical Distributions of Horizontal Velocities Used in Moment of Momentum Method

์—ฌ๊ธฐ์„œ, i๋Š” 1, 2; t๋Š” ์‹œ๊ฐ„; PIC5066.gif๋Š” ๊ฐ๊ฐ x, y๋ฐฉํ–ฅ์œผ๋กœ์˜ ๋‹จ์œ„ ํญ๋‹น ์œ ๋Ÿ‰; g๋Š” ์ค‘๋ ฅ๊ฐ€์†๋„; h๋Š” ์ˆ˜์‹ฌ; H๋Š” ๋ฐ”๋‹ฅ๊ณ ; PIC5076.gif๋Š” ij๋ฐฉํ–ฅ์œผ๋กœ ์ž‘์šฉํ•˜๋Š” ์—ฐ์งํ‰๊ท  ๋‚œ๋ฅ˜ ์ „๋‹จ์‘๋ ฅ; PIC5097.gif๋Š” ๋ฐ”๋‹ฅ ์ „๋‹จ๋ ฅ; PIC50B7.gif๋Š” ๊ฐ๊ฐ ์ˆ˜๋ฉด์—์„œ x, y๋ฐฉํ–ฅ์œผ๋กœ ํ‰๊ท  ์œ ์†์— ๋น„ํ•ด ์ดˆ๊ณผ๋œ ์œ ์†์˜ ํฌ๊ธฐ; PIC50D7.gif์€ ํ‰๊ท  ์ˆ˜์‹ฌ์„ ๋‚˜ํƒ€๋‚ธ๋‹ค. ์œ„ ์‹์—์„œ ์•„๋ž˜ ์ฒจ์ž j์™€ k๋Š” ์•„์ธ์Šˆํƒ€์ธ ํ•ฉํ‘œ์‹œ๊ทœ์น™์„ ๋”ฐ๋ฅด๋ฉฐ k๋Š” i์™€ ๊ฐ™์ง€ ์•Š๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ์ด ๋ฐฉ๋ฒ•์€ ์ฒœ์ˆ˜๋ฐฉ์ •์‹ ์ด์™ธ์— Eq. (3)๊ณผ ๊ฐ™์€ ์ถ”๊ฐ€์ ์ธ ๋‘ ๊ฐœ์˜ ์ˆ˜์†ก๋ฐฉ์ •์‹์„ ๋” ํ’€์–ด์•ผ ํ•˜๋ฏ€๋กœ, ๊ณ„์‚ฐ๋Ÿ‰์ด ๋งŽ๊ณ  ํšก๋ฐฉํ–ฅ ์œ ์†์˜ ๋‚˜์„ ํ˜• ์—ฐ์ง ๋ถ„ํฌ๋ฅผ ์ž˜ ๋ฐ˜์˜ํ•˜์ง€ ๋ชปํ•˜๋ฉฐ, ๋ฐ”๋‹ฅ์—์„œ์˜ ๋ฌดํ™œ์กฐ๊ฑด์„ ๋งŒ์กฑํ•˜์ง€ ๋ชปํ•˜๋Š” ๋‹จ์ ์ด ์žˆ๋‹ค.

๋งŒ๊ณก๋ถ€์—์„œ์˜ ์ด์ฐจ๋ฅ˜ ์œ ์†๊ตฌ์กฐ๋ฅผ ์ฒœ์ˆ˜ํ๋ฆ„ ์ˆ˜์น˜๋ชจ์˜์— ๋ฐ˜์˜ํ•˜๊ธฐ ์œ„ํ•œ ๋‘ ๋ฒˆ์งธ ๋ฐฉ๋ฒ•์ธ ๋ถ„์‚ฐ์‘๋ ฅ๋ฒ•์€ ๋‹ค์Œ๊ณผ ๊ฐ™๋‹ค. 3์ฐจ์› Navier- Stokes ๋ฐฉ์ •์‹์„ ์‹œ๊ฐ„ ํ‰๊ท ํ•˜๋ฉด 3์ฐจ์› Reynolds ๋ฐฉ์ •์‹์„ ์–ป๊ฒŒ ๋˜๋ฉฐ, ์ด๋ฅผ ์ˆ˜์‹ฌ ํ‰๊ท ํ•˜๋ฉด ์•„๋ž˜์™€ ๊ฐ™์€ ์—ฐ์ง๋ฐฉํ–ฅ์œผ๋กœ ํ‰๊ท ๋œ ๋ฐฉ์ •์‹์ด ๋„์ถœ๋œ๋‹ค.

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์—ฌ๊ธฐ์„œ, h๋Š” ์ˆ˜์‹ฌ; t๋Š” ์‹œ๊ฐ„, xi๋Š” i = 1์ธ ๊ฒฝ์šฐ x๋ฐฉํ–ฅ, 2์ธ ๊ฒฝ์šฐ y๋ฐฉํ–ฅ; PIC52ED.gif๋Š” ์ˆ˜์‹ฌ ํ‰๊ท  ์œ ์†; H๋Š” ํ•˜์ƒ๊ณ ; v๋Š” ๋‚œ๋ฅ˜ ๋™์ ์„ฑ ๊ณ„์ˆ˜; g๋Š” ์ค‘๋ ฅ ๊ฐ€์†๋„; n์€ ์กฐ๋„๊ณ„์ˆ˜๋ฅผ ์˜๋ฏธํ•œ๋‹ค. ๊ธฐ์กด์˜ ์ฒœ์ˆ˜ํ๋ฆ„ ๋ชจํ˜•์€ ์—ฐ์ง๋ฐฉํ–ฅ์œผ๋กœ ๊ท ๋“ฑํ•œ ์œ ์† ๋ถ„ํฌ๋ฅผ ๊ฐ€์ •ํ•˜๋ฏ€๋กœ, Eq. (4)์˜ ์ˆ˜์‹ฌ ์ ๋ถ„ํ•ญ์ด ํฌํ•จ๋œ ์ฒซ ๋ฒˆ์งธ, ๋‘ ๋ฒˆ์งธ ๋ฐ ๋„ค ๋ฒˆ์งธ ํ•ญ์ด ์—ฐ์งํ‰๊ท  ์œ ์†๊ณผ ์ˆ˜์‹ฌ์œผ๋กœ ํ‘œํ˜„๋˜์–ด ์ผ๋ฐ˜์ ์ธ ์šด๋™๋Ÿ‰๋ฐฉ์ •์‹์ด ๋œ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๊ณก์„ ๋ถ€์—์„œ์˜ PIC52EE.gif์˜ ์—ฐ์ง๋ฐฉํ–ฅ ๋ถ„ํฌ๋Š” ๊ท ์ผํ•˜์ง€ ์•Š์œผ๋ฏ€๋กœ ์ด๋ฅผ ๋ฐ˜์˜ํ•˜๊ธฐ ์œ„ํ•ด ์ข…ํšก๋ฐฉํ–ฅ ์œ ์†(PIC52FF.gif)์„ ํ‰๊ท (PIC5310.gif)๊ณผ ์ด๋กœ๋ถ€ํ„ฐ์˜ ๋ณ€๋™๋Ÿ‰(PIC5330.gif)์˜ ํ•ฉ์œผ๋กœ ์ •์˜ํ•˜๊ณ  Eq. (4)์— ๋Œ€์ž…ํ•˜๋ฉด ๋‘ ๋ฒˆ์งธ ํ•ญ์ธ ์ด์†ก ๊ฐ€์†๋„ํ•ญ์ด ๋‹ค์Œ๊ณผ ๊ฐ™์ด ํ‘œํ˜„๋œ๋‹ค.

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์œ„ ์‹์˜ ์šฐ๋ณ€์˜ ์ฒซ ๋ฒˆ์งธ ํ•ญ์€ ์ˆ˜์‹ฌํ‰๊ท  ํ๋ฆ„์— ์˜ํ•œ ์ด์†ก ๊ฐ€์†๋„ํ•ญ์ด๋ฉฐ, ์šฐ๋ณ€์˜ ๋‘ ๋ฒˆ์งธ ํ•ญ์€ ์ˆ˜์‹ฌํ‰๊ท  ์œ ์†๊ณผ ์—ฐ์ง๋ฐฉํ–ฅ์„ ๋”ฐ๋ผ ๋ณ€ํ™”ํ•˜๋Š” ์œ ์† ๋ถ„ํฌ์ฐจ์— ์˜ํ•ด ์ƒ์„ฑ๋˜๋Š” ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์— ํ•ด๋‹นํ•œ๋‹ค. ๋”ฐ๋ผ์„œ ์ถ”๊ฐ€์ ์œผ๋กœ ์ƒ์„ฑ๋œ ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์„ PIC54E8.gif๋กœ ํ‘œํ˜„ํ•˜๋ฉด Eq. (4)๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์€ ํ˜•ํƒœ๋กœ ๋‚˜ํƒ€๋‚œ๋‹ค.

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PIC57F9.gif        (6b)

์œ„ ์‹์— ๋‚˜ํƒ€๋‚œ ๋ฐ”์™€ ๊ฐ™์ด ์ด์ฐจ๋ฅ˜์˜ ์˜ํ–ฅ์„ ๋ฐ˜์˜ํ•˜๊ธฐ ์œ„ํ•ด ๋ถ„์‚ฐ์‘๋ ฅ ๋ฐฉ๋ฒ•์„ ์‚ฌ์šฉํ•˜๋Š” ๊ฒฝ์šฐ ์œ ์†์˜ ์—ฐ์ง ํ‰๊ท  ๊ฐ’๊ณผ ๋ณ€ํ™”๋Ÿ‰์˜ ์ฐจ๊ฐ€ ์ ๋ถ„ ๊ฐ€๋Šฅํ•˜๋‹ค๋ฉด ์–ด๋– ํ•œ ์œ ์†๋ถ„ํฌ์—๋„ ์ ์šฉํ•  ์ˆ˜ ์žˆ๋Š” ์ด์ ์ด ์žˆ์œผ๋ฉฐ, ๋˜ํ•œ VAM๊ณผ ๊ฐ™์€ ์ด์ฐจ๋ฅ˜ ํ•ด์„ ๋ชจํ˜•์—์„œ ์ด์šฉํ•˜๋Š” ๋ถ€์ˆ˜์ ์ธ ์ˆ˜์†ก๋ฐฉ์ •์‹์„ ํ’€ ํ•„์š”๊ฐ€ ์—†๋Š” ์žฅ์ ์ด ์žˆ๋‹ค.

์ฒœ์ˆ˜ํ๋ฆ„ํ•ด์„์—์„œ ์ด์ฐจ๋ฅ˜์˜ ์˜ํ–ฅ์„ ๊ณ ๋ คํ•˜๊ธฐ ์œ„ํ•ด ๋ถ„์‚ฐ์‘๋ ฅ๋ฒ•์„ ๋„์ž…ํ•œ ๊ตญ๋‚ด์˜ ์—ฐ๊ตฌ๋กœ๋Š” Kim ๋“ฑ(2009), Kim๊ณผ Choi(2009) ๋ฐ Song ๋“ฑ(2012)์„ ๊ผฝ์„ ์ˆ˜ ์žˆ๋‹ค. ์ด๋“ค์€ ๋ชจ๋‘ de Vriend(1977)๊ฐ€ ์ œ์•ˆํ•œ ๋กœ๊ทธํ•จ์ˆ˜ ํ˜•ํƒœ์˜ ์ข…๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง๋ถ„ํฌ์‹๊ณผ ๋น„์„ ํ˜• ๋กœ๊ทธํ•จ์ˆ˜์˜ ์ ๋ถ„ ์กฐํ•ฉํ˜• ํšก๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง๋ถ„ํฌ ์‹์„ ์ฒœ์ˆ˜๋ฐฉ์ •์‹์— ๋Œ€์ž…ํ•˜์—ฌ ์ถ”๊ฐ€์ ์œผ๋กœ ๋ฐœ์ƒํ•˜๋Š” ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์— ์˜ํ•ด ์ด์ฐจ๋ฅ˜์˜ ์˜ํ–ฅ์„ ๋ฐ˜์˜ํ•˜์˜€๋‹ค. Kim ๋“ฑ(2009)๊ณผ Kim๊ณผ Choi(2009)๋Š” ๋ณด์กดํ˜• ์ฒœ์ˆ˜๋ฐฉ์ •์‹์— CDG ๊ธฐ๋ฒ•(Ghanem, 1995)์„ ์ ์šฉํ•˜์—ฌ ๋ถ„์‚ฐ์‘๋ ฅ ์œ ๋ฌด์— ๋”ฐ๋ฅธ Rozovskii์˜ 180๋„ ๋งŒ๊ณก์ˆ˜๋กœ ๋ฐ 10 m ๊ธธ์ด์˜ ๋งŒ๊ณก๋ถ€๊ฐ€ 3๊ฐœ ์กด์žฌํ•˜๋Š” Kinoshita ์ˆ˜๋กœ์—์„œ ๊ฐœ๋ฐœ๋œ ๋ชจํ˜•์„ ๊ฒ€์ฆํ•˜์˜€๋‹ค. Song ๋“ฑ(2012)์€ ๋™์ผํ•œ de Vriend์˜ ์ˆ˜ํ•™์  ๋ชจํ˜•์„ ๋น„๋ณด์กดํ˜• ์ฒœ์ˆ˜๋ฐฉ์ •์‹์— ์ ์šฉํ•˜๊ณ  SU/PG ๊ธฐ๋ฒ•์— ์˜ํ•ด ์ด์‚ฐํ™”ํ•˜์—ฌ, Rozovskii์˜ ๋งŒ๊ณก์ˆ˜๋กœ, ๋ณธ๋ฅ˜์™€ ์ง€๋ฅ˜๊ฐ€ 90๋„๋กœ ํ•ฉ๋ฅ˜ํ•˜๋Š” ์‹คํ—˜์ˆ˜๋กœ ๋ฐ ๋‚จ๊ฐ•๋Œ ํ•˜๋ฅ˜๋ถ€ 4.7 km ์‚ฌํ–‰ ๊ตฌ๊ฐ„์— ๊ฐœ๋ฐœ๋œ ๋ชจํ˜•์„ ์ ์šฉํ•˜๊ณ  ์šด๋™๋Ÿ‰๋ฐฉ์ •์‹์˜ ๊ฐ ํ•ญ์— ๋น„ํ•ด ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์ด ๊ฐ€์ง€๋Š” ํฌ๊ธฐ ๋ฐ ์ง€๋ฐฐ๋ ฅ์„ ์ œ์‹œํ•˜์˜€๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ Song ๋“ฑ(2012)์˜ ์—ฐ๊ตฌ์—์„œ๋Š” ๋‹ค์–‘ํ•œ ์‚ฌํ–‰ ๊ฐ๋„๋ฅผ ๊ฐ€์ง€๋Š” ์‹คํ—˜์ˆ˜๋กœ์—์„œ ๋ถ„์‚ฐ์‘๋ ฅ ๋ชจํ˜•์˜ ์œ ํšจ์„ฑ ๋ฐ ์ ์šฉ์„ฑ์„ ๊ฒ€์ฆํ•˜์ง€ ๋ชปํ•˜์˜€๋‹ค. ๋ถ„์‚ฐ์‘๋ ฅ์„ ์ด์šฉํ•˜์—ฌ ์ด์ฐจ๋ฅ˜์˜ ์˜ํ–ฅ์„ ํ•ด์„ํ•œ ๊ตญ์™ธ ์—ฐ๊ตฌ๋Š” Flokstra(1977)์„ ์‹œ์ž‘์œผ๋กœ Molls์™€ Chaudhry(1995), Hsieh์™€ Yang(2003), Begnudelli ๋“ฑ(2010) ๋“ฑ์ด ์žˆ์œผ๋ฉฐ, ์ด๋“ค์€ ์ข…ํšก๋ฐฉ์œผ๋กœ ์•ฝ๊ฐ„์”ฉ ๋‹ค๋ฅธ ์—ฐ์ง ์œ ์† ๋ถ„ํฌ์‹์„ ์ด์šฉํ•˜์—ฌ ๋ถ„์‚ฐ์‘๋ ฅ ๊ธฐ๋ฒ•์„ ์ ์šฉํ•˜์˜€๋‹ค. de Vriend(1977)์˜ ์ˆ˜ํ•™์  ๋ชจํ˜•์— ๊ธฐ์ดˆํ•œ ๋ถ„์‚ฐ์‘๋ ฅ๋ฒ•์€ ํƒ„ํƒ„ํ•œ ์ด๋ก ์  ๊ธฐ๋ฐ˜์„ ๊ฐ€์ง€๊ณ  ์žˆ์œผ๋ฉฐ, ๋ฐ”๋‹ฅ์—์„œ์˜ ๋ฌดํ™œ์กฐ๊ฑด์„ ์ž˜ ๋งŒ์กฑ์‹œํ‚ค๊ณ , ๊ธฐ์กด์˜ ์‹คํ—˜๊ฒฐ๊ณผ์™€๋„ ์ž˜ ์ผ์น˜ํ•˜๋Š” ์žฅ์ ์ด ์žˆ๋‹ค (Song ๋“ฑ, 2012).

3. ๋ถ„์‚ฐ์‘๋ ฅ ๋ชจํ˜•

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” Eq. (6a)์— ์ƒˆ๋กญ๊ฒŒ ์ถ”๊ฐ€๋œ PIC5809.gif๋ฅผ ๋ชจํ˜•ํ™”ํ•˜๊ธฐ ์œ„ํ•ด์„œ de Vriend(1977)๊ฐ€ ์„ญ๋™๋ฒ•์„ ์ ์šฉํ•˜์—ฌ ์œ ๋„ํ•œ ์ˆ˜ํ•™์  ๋ชจํ˜•์„ ์ด์šฉํ•˜์˜€๋‹ค. de Vriend(1977)์— ์˜ํ•ด ์ œ์•ˆ๋œ ์ง๊ต์ขŒํ‘œ๊ณ„์—์„œ์˜ ์ข…ํšก๋ฑกํ–ฅ ์œ ์†์˜ ์—ฐ์ง ์œ ์† ๋ถ„ํฌ์‹์€ ๋‹ค์Œ๊ณผ ๊ฐ™๋‹ค.

PIC5858.gif                    (7a)

PIC5888.gif                    (7b)

์—ฌ๊ธฐ์„œ PIC5899.gif์€ PIC58B9.gif๋ฐฉํ–ฅ์˜ ์ˆ˜์‹ฌ์ ๋ถ„๋œ ์œ ์†; PIC58CA.gif์€ PIC58DA.gif๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง๋ถ„ํฌ; PIC58FB.gif๋Š” PIC591B.gif๋ฐฉํ–ฅ ์ˆ˜์‹ฌํ‰๊ท  ์œ ์†; PIC592B.gif๋Š” PIC593C.gif๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง๋ถ„ํฌ; h๋Š” ์ˆ˜์‹ฌ; PIC594D.gif๋Š” ๋ฐ”๋‹ฅ์œผ๋กœ๋ถ€ํ„ฐ์˜ ๋ฌด์ฐจ์› ๊ฑฐ๋ฆฌ๋ฅผ ์˜๋ฏธํ•˜๋ฉฐ, PIC595D.gif๊ณผ PIC595E.gif๋Š” ์•„๋ž˜์™€ ๊ฐ™์ด ํ‘œํ˜„๋œ๋‹ค.

PIC598E.gif                           (8a)

PIC5B06.gif 

PIC5B26.gif                           (8b)

PIC5C8F.gif 

์œ„ ์‹์—์„œ PIC5CAF.gif๋Š” ์ˆ˜์‹ฌ ๋Œ€ ๊ณก๋ฅ ๋ฐ˜๊ฒฝ์˜ ๋น„๋กœ ์ผ๋ฐ˜์ ์œผ๋กœ 1 ์ดํ•˜์˜ ๊ฐ’์„ ๊ฐ€์ง€๋ฉฐ, PIC5CC0.gif๋Š” ์œ ์†์˜ Euclidian norm์ด๋‹ค.

์ฃผ ํ๋ฆ„ ํ•จ์ˆ˜ (PIC5CE0.gif)์™€ ์ด์ฐจ ํ๋ฆ„ ํ•จ์ˆ˜(PIC5CF1.gif)๋Š” ์•„๋ž˜์™€ ๊ฐ™์ด ์ •์˜๋˜๋ฉฐ Chรฉzy ๊ณ„์ˆ˜ C์— ๋”ฐ๋ผ Fig. 3๊ณผ ๊ฐ™์ด ์—ฐ์ง๋ฐฉํ–ฅ ์œ ์†๋ถ„ํฌ๊ฐ€ ๋ณ€ํ™”๋œ๋‹ค.

PIC5D20.gif                     (9a)

PIC5D9E.gif    (9b)

์œ„ ์‹์—์„œ k๋Š” von Karman ์ƒ์ˆ˜ (0.4)์ด๊ณ  PIC5DBF.gif๊ณผ PIC5DEF.gif๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์€ ์‹์œผ๋กœ ํ‘œํ˜„๋œ๋‹ค.

PIC5E2E.gif  

PIC5E5E.gif                         (10)

Eq. (7)๊ณผ Eq. (9)์— ๋”ฐ๋ฅด๋ฉด, ์—ฐ์ง๋ฐฉํ–ฅ ์œ ์†๋ถ„ํฌ๋Š” ์ฃผ ํ๋ฆ„ ์œ ์†์˜ ๋กœ๊ทธ๋ถ„ํฌ์™€ Chรฉzy ๋ฐ von Karman ์ƒ์ˆ˜๋ฅผ ํฌํ•จํ•˜๋Š” ๋น„์„ ํ˜• ์ด์ฐจ ํ๋ฆ„ ํ•จ์ˆ˜์˜ ๊ฒฐํ•ฉ์œผ๋กœ ์ด๋ฃจ์–ด์ ธ ์žˆ์Œ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ๋˜ํ•œ ์ด์ฐจ ํ๋ฆ„ํ•จ์ˆ˜๋Š” ์‚ฌํ–‰์— ์˜ํ•œ ์ฃผ ํ๋ฆ„์˜ ๋ฐฉํ–ฅ์— ์ˆ˜์ง์ธ ์„ฑ๋ถ„๊ณผ ์ฃผ ํ๋ฆ„์˜ ์ข…๋ฐฉํ–ฅ ๊ฐ€์†์— ์˜ํ•ด ๋ฐœ์ƒํ•˜๋Š” ์ฃผ ํ๋ฆ„๋ฐฉํ–ฅ ์ด์ฐจ๋ฅ˜ ์„ฑ๋ถ„์œผ๋กœ ๊ตฌ์„ฑ๋˜์–ด ์žˆ๋‹ค. ์ด๋Š” ์œ ์„ ๋ฐฉํ–ฅ ์šด๋™๋Ÿ‰์„ ๋งŒ๊ณก๋ถ€ ๋‚ด์ธก์œผ๋กœ๋ถ€ํ„ฐ ์™ธ์ธก์œผ๋กœ ์ด๋™์‹œ์ผœ ์™ธ์ธก์—์„œ์˜ ์ฃผ ํ๋ฆ„์œ ์†์ด ์ฆ๊ฐ€๋˜๋Š” ํ˜„์ƒ์„ ๋ฐ˜์˜ํ•˜๊ธฐ ์œ„ํ•œ ๊ฒƒ์ด๋‹ค.

Eq. (7)์— ์œ„์—์„œ ์ •์˜ํ•œ ์œ ์†๋ถ„ํฌ๋ฅผ ํฌํ•จํ•˜๊ณ , ์ด๋ฅผ ๋‹ค์‹œ Eq. (6b)์— ๋Œ€์ž…ํ•˜์—ฌ ํ…์„œํ˜• ๋ถ„์‚ฐ์‘๋ ฅ์„ ๊ณ„์‚ฐํ•˜๋ฉด ๋‹ค์Œ๊ณผ ๊ฐ™์€ ์„ฑ๋ถ„์œผ๋กœ ๊ตฌ์„ฑ๋œ๋‹ค. ์ฒซ ๋ฒˆ์งธ ๋ถ„์‚ฐ์‘๋ ฅํ•ญ (PIC5E6F.gif)์€ PIC5E8F.gif๋ฐฉํ–ฅ ์œ ์†์˜ ํ‰๊ท ๊ฐ’๊ณผ ๋ณ€๋™๊ฐ’์˜ ์ฐจ์˜ ๊ณฑ์— ์˜ํ•ด ๋‹ค์Œ๊ณผ ๊ฐ™์ด ๊ณ„์‚ฐ๋œ๋‹ค.

PIC5F3C.gif 

PIC5F6C.gif       (11)

์—ฌ๊ธฐ์„œ

PIC5FBB.gif  PIC5FFA.gif   (12)

๋‘ ๋ฒˆ์งธ ์„ฑ๋ถ„(PIC601A.gif)์€ PIC603B.gif๋ฐฉํ–ฅ๊ณผ PIC604B.gif๋ฐฉํ–ฅ ์œ ์†์˜ ์ฐจ์— ์˜ํ•ด ๋ฐœ์ƒํ•˜๋ฉฐ ๋‹ค์Œ๊ณผ ๊ฐ™์ด ๊ณ„์‚ฐ๋œ๋‹ค.

PIC6156.jpg

Fig. 3. De Vriendโ€™s Primary and Secondary Flow Functions

PIC6223.gif            (13)

PIC6291.gif

๋งˆ์ง€๋ง‰ ์„ฑ๋ถ„ (PIC62A2.gif)์€ PIC62B3.gif๋ฐฉํ–ฅ ์œ ์†์˜ ์ฐจ์˜ ๊ณฑ์— ์˜ํ•ด ์ƒ์„ฑ๋˜๋ฉฐ ์•„๋ž˜์™€ ๊ฐ™๋‹ค.

PIC6311.gif

PIC6341.gif       (14)

Eq. (10)๊ณผ Eq. (12)์— ํฌํ•จ๋œ ์ ๋ถ„์€ ์‚ฌ๋‹ค๋ฆฌ๊ผด ๊ทœ์น™์— ์˜ํ•ด ๊ณ„์‚ฐํ•  ์ˆ˜ ์žˆ๋‹ค.

4. ์ˆ˜์น˜๋ชจ์˜

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ์ด์ฐจ๋ฅ˜์˜ ์˜ํ–ฅ์„ ๋ถ„์‚ฐ์‘๋ ฅ์„ ์ด์šฉํ•˜์—ฌ ๋ฐ˜์˜ํ•œ Song ๋“ฑ(2012)์˜ ์ฒœ์ˆ˜ํ๋ฆ„ ํ•ด์„ ์ˆ˜์น˜๋ชจํ˜•์„ 30๋„, 90๋„ ๋ฐ 270๋„์˜ ๋งŒ๊ณก๋ถ€๋ฅผ ํฌํ•จํ•˜๋Š” ์ˆ˜๋กœ์— ์ ์šฉํ•˜์—ฌ ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์˜ ์œ ๋ฌด์— ๋”ฐ๋ฅธ ๊ณก์„ ์ˆ˜๋กœ์—์„œ์˜ ํ๋ฆ„ํŠน์„ฑ์„ ๋ถ„์„ํ•˜์˜€๋‹ค. ์ˆ˜์น˜๊ธฐ๋ฒ•์œผ๋กœ๋Š” ์œ ์†๊ณผ ํ˜•์ƒํ•จ์ˆ˜ ํŽธ๋ฏธ๋ถ„์˜ ๋‚ด์ ์— ์˜ํ•ด ์ƒํ–ฅ ๊ฐ€์ค‘๋œ ์„ญ๋™ํ•จ์ˆ˜๊ฐ€ ์œ ์ฒด์˜ ํ๋ฆ„๋ฐฉํ–ฅ์œผ๋กœ ์ž‘์šฉํ•˜๊ฒŒ ๋˜์–ด, ์ฒœ์ˆ˜๋ฐฉ์ •์‹์˜ ๋น„์„ ํ˜• ์ด์†กํ•ญ์˜ ๋ถˆ์•ˆ์ •์„ฑ์„ ๊ฐ์†Œ์‹œํ‚ค๋Š” SU/PG ๊ธฐ๋ฒ•(Hughes์™€ Brooks, 1979; Song๊ณผ Seo, 2012)์„ ์ ์šฉํ•˜์˜€๋‹ค.

4.1 30๋„ ๊ณก์„ ์ˆ˜๋กœ

Fig.4(a)์™€ ๊ฐ™์ด ์ธก๋ฒฝ๊ฒฝ์‚ฌ 1V:2H์˜ ์‚ฌ๋‹ค๋ฆฌ๊ผด ๋‹จ๋ฉด์„ ๊ฐ€์ง€๊ณ  30๋„์˜ ๋งŒ๊ณก๋ถ€๋ฅผ ํฌํ•จํ•˜๋Š” ๊ณก์„ ์ˆ˜๋กœ์—์„œ ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์˜ ์œ ๋ฌด์— ๋”ฐ๋ฅธ ์œ ์†๋ถ„ํฌ๋ฅผ ๋น„๊ตํ•˜์˜€๋‹ค. 220๊ฐœ(์ข…๋ฐฉํ–ฅ 22๊ฐœ x ํšก๋ฐฉํ–ฅ 10๊ฐœ)์™€ 880๊ฐœ(์ข…๋ฐฉํ–ฅ 44๊ฐœ x ํšก๋ฐฉํ–ฅ 20๊ฐœ)์˜ 2๊ฐ€์ง€ ๊ฒฉ์ž ํ•ด์ƒ๋„์— ๋”ฐ๋ฅธ Sec.1์—์„œ์˜ ํšก๋ฐฉํ–ฅ ์œ ์†๊ฐ’์„ Maynord(1996)์˜ ์‹คํ—˜์ž๋ฃŒ์™€ ๋น„๊ตํ•˜์—ฌ Fig. 4(b)์— ๋„์‹œํ•˜์˜€๋‹ค. 220๊ฐœ์˜ ์‚ฌ๊ฐ๋ง์— ์˜ํ•œ ๊ฒฐ๊ณผ๋Š” Sec.1์—์„œ์˜ ์œ ์†๊ฐ’์„ ๊ณผ๋Œ€ ์‚ฐ์ •ํ•˜๋ฏ€๋กœ, ์ˆ˜์น˜๋ชจ์˜์— ์ด์šฉํ•œ ์ ˆ์  ์ˆ˜์™€ ์š”์†Œ ์ˆ˜๋Š” Table 1 ๋ฐ Fig. 4(a)์— ์ œ์‹œ๋œ ๊ฒฉ์ž๋ง๊ณผ ๊ฐ™์ด ๊ฐ๊ฐ 945๊ฐœ ๋ฐ 880๊ฐœ๋กœ ๊ฒฐ์ •ํ•˜์˜€๋‹ค. 30๋„ ์ˆ˜๋กœ์˜ ์ˆ˜์น˜๋ชจ์˜์—์„œ๋Š” ๋ฒฝ๋ฉด๊ฒฝ๊ณ„ ์กฐ๊ฑด์„ ๋ฌดํ™œ(no-slip) ์กฐ๊ฑด์œผ๋กœ ๋ถ€์—ฌํ•˜์—ฌ Maynord(1996)์˜ ์‹ค์ธก์ž๋ฃŒ์™€ Bernard์™€ Schneider(1992)์— ์ œ์‹œ๋œ STREMR ๋ชจํ˜•์˜ ๋ชจ์˜ ์กฐ๊ฑด์— ๋ณด๋‹ค ๊ทผ์‚ฌํ•˜๋„๋ก ํ•˜์˜€๋‹ค. ์ƒ๋ฅ˜๋‹จ ์œ ๋Ÿ‰์กฐ๊ฑด์€ 0.566 cms, ํ•˜๋ฅ˜๋‹จ ์ˆ˜์‹ฌ๊ฒฝ๊ณ„์กฐ๊ฑด์€ 0.3 m๋กœ ์ž…๋ ฅํ•˜์˜€์œผ๋ฉฐ ์ด ๊ฒฝ์šฐ Fr ์ˆ˜๋Š” 0.518์ด๋‹ค. Maynord(1996)์˜ ์ˆ˜๋ฆฌ์‹คํ—˜์กฐ๊ฑด์„ ๋ฐ”ํƒ•์œผ๋กœ ํ•˜์—ฌ ์กฐ๋„๊ณ„์ˆ˜๋Š” 0.021๋กœ ์„ค์ •ํ•˜์˜€๋‹ค.

Fig. 5์— ์œ ์† ๋ฒกํ„ฐ๋„์™€ 30๋„ ๋งŒ๊ณก๋ถ€ ๋ถ€๊ทผ์—์„œ์˜ ๋“ฑ์œ ์†๋„๋ฅผ ๋„์‹œํ•˜์˜€๋‹ค. ๋ฌดํ™œ์กฐ๊ฑด์„ ์ž…๋ ฅํ•˜์˜€๊ธฐ ๋•Œ๋ฌธ์— ์ƒ๋ฅ˜๋‹จ ๊ฒฝ๊ณ„๋ฉด์— ๋ถ€์—ฌ๋œ ๊ท ์ผํ•œ ์œ ์†๋ถ„ํฌ๊ฐ€ ์ ์ฐจ ํฌ๋ฌผ์„ ํ˜•์œผ๋กœ ๋‹ˆํƒ€๋‚˜๋Š” ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. A ์˜์—ญ์˜ ๋“ฑ์œ ์†๋„๋ฅผ ํ™•๋Œ€ํ•œ ๊ทธ๋ฆผ์—์„œ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๊ฒฝ์šฐ, 1.0 m/s์˜ ์ตœ๋Œ€ ์œ ์†์„ ์ด ๋งŒ๊ณก๋ถ€ ์™ธ์ธก์œผ๋กœ ๋ณด๋‹ค ํŽธํ–ฅ๋˜์–ด ๋‚˜ํƒ€๋‚ฌ๋‹ค. ์ด๋Š” Sec. 1๊ณผ Sec. 2์—์„œ ์ขŒ์•ˆ์œผ๋กœ๋ถ€ํ„ฐ ์šฐ์•ˆ ๋ฐฉํ–ฅ์œผ๋กœ์˜ ํšก๋ฐฉํ–ฅ ๊ฑฐ๋ฆฌ(y)๋ฅผ ์ˆ˜๋กœ ํญ(W)์œผ๋กœ ๋‚˜๋ˆ„์–ด ๋ฌด์ฐจ์›ํ™”(y/W)ํ•˜๊ณ  ํšก๋ฐฉํ–ฅ ์œ ์†๋ถ„ํฌ๋ฅผ ๋„์‹œํ•œ Fig. 6์—์„œ ๋ณด๋‹ค ๋ช…ํ™•ํ•˜๊ฒŒ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค. Fig. 6(a)์˜ Sec. 1์—์„œ ์ ์„ ์œผ๋กœ ํ‘œ์‹œํ•œ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•˜์ง€ ์•Š์€ ๊ฒฝ์šฐ์— ๋น„ํ•ด ์‹ค์„ ์œผ๋กœ ํ‘œ์‹œํ•œ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๊ฒฝ์šฐ์˜ ์œ ์† ๋ถ„ํฌ๊ฐ€ ๋ณด๋‹ค ๋งŒ๊ณก๋ถ€ ์™ธ์ธก์œผ๋กœ ์ด๋™ํ•˜์—ฌ ๊ฒ€์€ ์ ์œผ๋กœ ํ‘œ์‹œํ•œ Maynord(1996)์˜ ์ˆ˜๋ฆฌ์‹คํ—˜ ๊ฒฐ๊ณผ์™€ ์ž˜ ์ผ์น˜ํ•˜์˜€๋‹ค. ์ด์™€ ๊ฐ™์€ ํ˜„์ƒ์€ ๋งŒ๊ณก๋ถ€๋ฅผ ํ†ต๊ณผํ•œ ํ›„ ์ง์„ ๋ถ€์— ํ•ด๋‹นํ•˜๋Š” Sec. 2์—์„œ๋„ ๋™์ผํ•˜๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค(Fig. 6(b)). 30๋„ ์ˆ˜๋กœ ๋ชจ์˜์—์„œ๋Š” Bernard์™€ Schneider(1992)์— ์ œ์‹œ๋œ STREMR ๋ชจํ˜•์˜ ์ˆ˜์น˜๋ชจ์˜ ๊ฒฐ๊ณผ๋ฅผ ์ด์šฉํ•˜์—ฌ ํšก๋ฐฉํ–ฅ ์œ ์†๋ถ„ํฌ๋ฅผ ๋น„๊ตํ•˜์˜€๋‹ค. STREMR ๋ชจํ˜•์€ ์ด์ฐจ๋ฅ˜์˜ ์˜ํ–ฅ์„ ๋‹จ์ˆœํžˆ ์œ ์„ ๋ฐฉํ–ฅ ์™€๋„์— ๊ด€ํ•œ ๊ฒฝํ—˜ ์ด์†ก์‹์— ์˜ํ•ด ๊ณ„์‚ฐํ•˜์—ฌ, ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๋ณธ ๋ชจํ˜•์— ๋น„ํ•ด ๋งŒ๊ณก๋ถ€์—์„œ ํ๋ฆ„์ด ์™ธ์ธก์œผ๋กœ ํŽธํ–ฅ๋˜๋Š” ์œ ์†๊ตฌ์กฐ๋ฅผ ์˜ฌ๋ฐ”๋ฅด๊ฒŒ ๋ฐ˜์˜ํ•˜์ง€ ๋ชปํ•˜์˜€์œผ๋ฉฐ, ์ˆ˜๋กœ์˜ ์ขŒ์•ˆ๊ณผ ์ค‘์•™ ๋ถ€๊ทผ์—์„œ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•˜์ง€ ์•Š์€ ๋ณธ ์—ฐ๊ตฌ์˜ ๋ชจ์˜ ๊ฒฐ๊ณผ์™€ ์œ ์‚ฌํ•œ ์œ ์†๊ฐ’์„ ๋ณด์˜€๋‹ค.

PIC6371.jpg

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(a) Finite Element and Flow Conditions

(b) Comparison of Velocities at Sec.1 According to mesh Resolutions

Fig. 4. Geometry, Finite Elements, Flow Conditions and mesh Dependency for 30 Degree Curved Channel

Table 1. Simulation Conditions for Curved Channels

Element info.

Boundary conditions

Parameters

Bend

Number of element

Number of node

Q (cms)

h (m)

n

h/Rc

Fr

30o

880

945

0.5660

0.300

0.021

0.0437

0.518

90o

1,728

1,885

0.0985

0.115

0.010

0.0135

0.345

270o

4,312

4,531

0.0235

0.064

0.010

0.0179

0.507

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Fig. 5. Velocity Vector and Influence of Dispersion Stresses in Region a for 30 Degree Curved Channel

4.2 90๋„ ๊ณก์„ ์ˆ˜๋กœ

์ œ์•ˆ๋œ ๋ชจํ˜•์˜ ๋‘ ๋ฒˆ์งธ ์ ์šฉ์‚ฌ๋ก€๋กœ Fig. 7(a)์™€ ๊ฐ™์ด ํญ 2.34 m์˜ ์ง์‚ฌ๊ฐํ˜• ๋‹จ๋ฉด์„ ๊ฐ€์ง€๊ณ  ๋‘ ๊ฐœ์˜ 90๋„ ๋งŒ๊ณก๋ถ€๋ฅผ ํฌํ•จํ•˜๋Š” ์ˆ˜๋กœ์—์„œ์˜ ์ˆ˜์น˜๋ชจ์˜ ๊ฒฐ๊ณผ๋ฅผ ์ˆ˜๋ฆฌ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ํƒ€ ๋ชจํ˜• ๋ชจ์˜๊ฒฐ๊ณผ์™€ ๋น„๊ตํ•˜์˜€๋‹ค. 432๊ฐœ(์ข…๋ฐฉํ–ฅ 72๊ฐœ x ํšก๋ฐฉํ–ฅ 6๊ฐœ)์™€ 1,728๊ฐœ(์ข…๋ฐฉํ–ฅ 144๊ฐœ x ํšก๋ฐฉํ–ฅ 12๊ฐœ)์˜ 2๊ฐ€์ง€ ๊ฒฉ์ž ํ•ด์ƒ๋„์— ๋”ฐ๋ฅธ Sec.7์—์„œ์˜ ํšก๋ฐฉํ–ฅ ์œ ์†๊ฐ’์„ Chang(1971)์˜ ์‹คํ—˜์ž๋ฃŒ์™€ ๋น„๊ตํ•˜์—ฌ Fig. 7(b)์— ๋„์‹œํ•˜์˜€๋‹ค. 432๊ฐœ์˜ ์‚ฌ๊ฐ๋ง์— ์˜ํ•œ ๊ฒฐ๊ณผ๋Š” Sec.7 ๋‹จ๋ฉด์˜ ์ค‘์•™ ๋ฐ ์™ธ์ธก์—์„œ ์œ ์†๊ฐ’์„ ๊ณผ๋Œ€ ์‚ฐ์ •ํ•˜๊ณ , ์„ฑ๊ทผ ๊ฒฉ์ž ํฌ๊ธฐ์— ์˜ํ•ด ๋ถ„์‚ฐ์‘๋ ฅ์— ์˜ํ•œ ํšก๋ฐฉํ–ฅ ์šด๋™๋Ÿ‰ ์ „๋‹ฌ์„ ์˜ฌ๋ฐ”๋ฅด๊ฒŒ ๋ฐ˜์˜ํ•˜์ง€ ๋ชปํ•˜๋ฏ€๋กœ, ์ˆ˜์น˜๋ชจ์˜์— ์ด์šฉํ•œ ์ ˆ์  ์ˆ˜์™€ ์š”์†Œ ์ˆ˜๋Š” Table 1 ๋ฐ Fig. 7(a)์— ์ œ์‹œ๋œ 1,885๊ฐœ ๋ฐ 1,728๊ฐœ๋กœ ๊ฒฐ์ •ํ•˜์˜€๋‹ค. ์ƒ๋ฅ˜๋‹จ ์œ ๋Ÿ‰์กฐ๊ฑด์€ 0.0985 cms, ํ•˜๋ฅ˜๋‹จ ์ˆ˜์‹ฌ๊ฒฝ๊ณ„์กฐ๊ฑด์€ 0.115 m๋กœ ์ž…๋ ฅํ•˜์˜€์œผ๋ฉฐ ์ด ๊ฒฝ์šฐ Fr ์ˆ˜๋Š” 0.345์ด๋‹ค. ์ˆ˜๋กœ์˜ ๋ฒฝ๋ฉด์—๋Š” ํ™œ๋™ ๊ฒฝ๊ณ„์กฐ๊ฑด์„ ๋ถ€์—ฌํ•˜์˜€์œผ๋ฉฐ, Chang(1971)์˜ ์ˆ˜๋ฆฌ์‹คํ—˜์กฐ๊ฑด์„ ๋ฐ”ํƒ•์œผ๋กœ ํ•˜์—ฌ ์กฐ๋„๊ณ„์ˆ˜๋Š” 0.010์œผ๋กœ ์„ค์ •ํ•˜์˜€๋‹ค.

PIC6430.jpg

PIC6460.jpg

Fig. 6. Velocity Comparisons Along the Transverse Sections of 30 Degree Curved Channel

PIC648F.jpg

PIC64CF.jpg

(a) Finite Elements and Flow Conditions

(b) Comparison of Velocities at Sec.7 According to Mesh Resolutions

Fig. 7. Geometry, Finite Elements and Flow Conditions for 90 Degree Curved Channel

๋‘ ๋ฒˆ์งธ ๋งŒ๊ณก๋ถ€ ์œ ์ž…์ง€์ ์˜ ์ธก์„ (Sec.5)์„ ํฌํ•จํ•˜์—ฌ 4๊ฐœ์˜ ํšก๋ฐฉํ–ฅ ์ธก์„ ์—์„œ์˜ ์œ ์†๋ถ„ํฌ๋ฅผ Fig. 8์— ๋‚˜ํƒ€๋ƒˆ๋‹ค. Chang(1971)์˜ ์ˆ˜๋ฆฌ์‹คํ—˜ ๊ฒฐ๊ณผ์™€ ๋ถ„์‚ฐ์‘๋ ฅ ์œ ๋ฌด์— ์˜ํ•œ ๋ณธ ์—ฐ๊ตฌ์˜ ์ˆ˜์น˜๋ชจ์˜ ๊ฒฐ๊ณผ, ์ด์ฐจ๋ฅ˜์˜ ์˜ํ–ฅ์„ VAM ๋ฐฉ๋ฒ•์œผ๋กœ ๋ฐ˜์˜ํ•œ Ghamry์™€ Steffler(2002)์˜ ๊ฒฐ๊ณผ๋ฅผ ๋น„๊ตํ•˜์˜€๋‹ค. ๋ชจ๋“  ๊ฒฐ๊ณผ์—์„œ ๊ณตํ†ต์ ์œผ๋กœ ๋‘ ๋ฒˆ์งธ ๋งŒ๊ณก๋ถ€์˜ ์‹œ์ (Sec.5)๋ถ€ํ„ฐ ๋งŒ๊ณก๋ถ€ ์ •์ (Sec.9)๊นŒ์ง€๋Š” ์ˆ˜๋กœ ๋‚ด์ธก์˜ ์œ ์†์ด ๋น ๋ฅด๊ฒŒ ๋ถ„ํฌํ•˜๋‹ค๊ฐ€ Sec.11๋ถ€ํ„ฐ๋Š” ์ ์ฐจ ๊ท ์ผํ•œ ์œ ์†์œผ๋กœ ๋ณ€ํ™”๋˜์–ด ๊ฐ€๋Š” ๊ฒƒ์„ ์ด ๊ทธ๋ฆผ์—์„œ ํ™•์ธํ•  ์ˆ˜ ์žˆ๋‹ค. ๋ถ„์‚ฐ์‘๋ ฅ ์œ ๋ฌด์— ๋”ฐ๋ฅธ ์œ ์†์„ ๋น„๊ตํ•ด ๋ณด๋ฉด Sec.9์ธ ๋งŒ๊ณก๋ถ€ ์ •์ ์—์„œ๋Š” ๋‘ ๊ฒฐ๊ณผ๊ฐ€ ์œ ์‚ฌํ•˜๊ฒŒ ๋‚˜ํƒ€๋‚ฌ์œผ๋‚˜, ๋งŒ๊ณก๋ถ€ ์œ ์ž…๋ถ€์— ํ•ด๋‹นํ•˜๋Š” Sec.5์™€ Sec.7์—์„œ๋Š” ๋ถ„์‚ฐ์‘๋ ฅ์„ ๋ฌด์‹œํ•œ ๊ฒฝ์šฐ ์ˆ˜๋กœ ๋‚ด์ธก์—์„œ๋Š” ์œ ์†์ด ๋‚ฎ๊ฒŒ ๋‚˜ํƒ€๋‚˜๊ณ  ์™ธ์ธก์—์„œ๋Š” ๋†’๊ฒŒ ๋‚˜ํƒ€๋‚˜ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๊ฒฝ์šฐ์— ๋น„ํ•ด ์œ ์† ๊ฒฝ์‚ฌ๊ฐ€ ์™„๋งŒํ•˜๊ฒŒ ๋ถ„ํฌํ•˜์˜€๋‹ค. ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๋ณธ ์—ฐ๊ตฌ์˜ ๋ชจํ˜•๊ณผ Ghamry์™€ Steffler(2002)์˜ ๋ชจ์˜ ๊ฒฐ๊ณผ๋ฅผ ๋น„๊ตํ•ด ๋ณด๋ฉด Sec.5์™€ Sec.7์˜ ์ขŒ์•ˆ๊ณผ Sec.9์™€ Sec.11์˜ ์šฐ์•ˆ์—์„œ์˜ ์œ ์†์ด ์„œ๋กœ ๋งค์šฐ ์œ ์‚ฌํ•˜๊ฒŒ ๋‚˜ํƒ€๋‚ฌ์ง€๋งŒ, Sec.7์˜ ์ˆ˜๋กœ ๋‚ด์ธก๊ณผ Sec.11์˜ ์ค‘์•™ ๋ถ€๋ถ„์—์„œ ๋ณธ ์—ฐ๊ตฌ์— ์˜ํ•œ ๋ชจํ˜•์˜ ๋ชจ์˜๊ฒฐ๊ณผ๊ฐ€ Chang(1971)์˜ ์ˆ˜๋ฆฌ์‹คํ—˜ ๊ฒฐ๊ณผ์— ๋ณด๋‹ค ๊ทผ์‚ฌํ•˜์˜€๋‹ค. ๋˜ํ•œ Sec. 9์˜ ์ค‘์•™๋ถ€๋ถ„์—์„œ ์œ ์†์ด ๋†’๊ฒŒ ๋‚˜ํƒ€๋‚˜๋Š” ํ˜„์ƒ์„ VAM ๋ชจํ˜•์— ๋น„ํ•ด ์ƒ๋Œ€์ ์œผ๋กœ ์ •ํ™•ํ•˜๊ฒŒ ์˜ˆ์ธกํ•˜์˜€๋‹ค. VAM ๋ชจํ˜•์€ ์ด์ฐจ๋ฅ˜์˜ 3์ฐจ์›์  ์œ ์† ๊ตฌ์กฐ๋ฅผ ๋ฐ˜์˜ํ•˜๊ธฐ ์œ„ํ•ด 10๊ฐœ์˜ ๋ฐฉ์ •์‹์„ ํ’€์–ด์•ผ ํ•˜๋Š” ๋ฒˆ๊ฑฐ๋กœ์›€์ด ์žˆ๊ณ  ๊ณ„์‚ฐ์‹œ๊ฐ„๋„ ์˜ค๋ž˜ ๊ฑธ๋ฆฌ๋Š” ๋‹จ์ ์ด ์žˆ๋‹ค.

4.3 270๋„ ๊ณก์„ ์ˆ˜๋กœ

๋ณธ ๋ชจํ˜•์˜ ์„ธ ๋ฒˆ์งธ ์ ์šฉ์‚ฌ๋ก€๋กœ Fig. 9(a)์™€ ๊ฐ™์ด ์™ธ์ธก ๋ฒฝ๋ฉด ๊ฒฝ์‚ฌ 1V:2H์˜ ์‚ฌ๋‹ค๋ฆฌ๊ผด ๋‹จ๋ฉด์„ ๊ฐ€์ง€๊ณ  270๋„์˜ ๋งŒ๊ณก๋ถ€๋ฅผ ํฌํ•จํ•˜๋Š” ์ˆ˜๋กœ์—์„œ ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์˜ ์œ ๋ฌด์— ๋”ฐ๋ฅธ ์œ ์†๋ถ„ํฌ๋ฅผ ๋น„๊ตํ•˜์˜€๋‹ค. 1,078๊ฐœ(์ข…๋ฐฉํ–ฅ 98๊ฐœ x ํšก๋ฐฉํ–ฅ 11๊ฐœ)์™€ 4,312๊ฐœ(์ข…๋ฐฉํ–ฅ 196๊ฐœ x ํšก๋ฐฉํ–ฅ 22๊ฐœ)์˜ 2๊ฐ€์ง€ ๊ฒฉ์ž ํ•ด์ƒ๋„์— ๋”ฐ๋ฅธ 90๋„ ๋‹จ๋ฉด์—์„œ์˜ ํšก๋ฐฉํ–ฅ ์œ ์†๊ฐ’์„ Hick ๋“ฑ(1996)์˜ ์‹คํ—˜์ž๋ฃŒ์™€ ๋น„๊ตํ•˜์—ฌ Fig. 9(b)์— ๋„์‹œํ•˜์˜€๋‹ค. 1,078๊ฐœ์˜ ์‚ฌ๊ฐ๋ง์— ์˜ํ•œ ๋ชจ์˜ ๊ฒฐ๊ณผ 90๋„ ๋‹จ๋ฉด์˜ ๋‚ด์ธก ๋ฐ ์ค‘์•™๋ถ€์—์„œ์˜ ์œ ์†์„ ๊ณผ์†Œ ์‚ฐ์ •ํ•˜๊ณ  ์™ธ์ธก์—์„œ๋Š” ๊ณผ๋Œ€ ์‚ฐ์ •ํ•˜๋ฉฐ, ๋˜ํ•œ 4,312๊ฐœ ๊ฒฉ์ž๋ง์˜ ๊ฒฝ์šฐ์— ๋น„ํ•ด ๋ถ„์‚ฐ์‘๋ ฅ์— ์˜ํ•œ ํšก๋ฐฉํ–ฅ ์šด๋™๋Ÿ‰์˜ ์ „๋‹ฌ์ด ์ •ํ™•ํ•˜๊ฒŒ ๋ฐ˜์˜๋˜์ง€ ๋ชปํ•˜๋ฏ€๋กœ, ์ˆ˜์น˜๋ชจ์˜์— ์ด์šฉํ•œ ์ ˆ์  ์ˆ˜์™€ ์š”์†Œ ์ˆ˜๋Š” Table 1 ๋ฐ Fig. 9(a)์— ์ œ์‹œ๋œ 4,531๊ฐœ ๋ฐ 4,312๊ฐœ๋กœ ๊ฒฐ์ •ํ•˜์˜€๋‹ค. ์ƒ๋ฅ˜๋‹จ ์œ ๋Ÿ‰์กฐ๊ฑด์€ 0.0235 cms, ํ•˜๋ฅ˜๋‹จ ์ˆ˜์‹ฌ๊ฒฝ๊ณ„์กฐ๊ฑด์€ 0.064 m๋กœ ์ž…๋ ฅํ•˜์˜€๋‹ค. ๋˜ํ•œ Hicks ๋“ฑ(1990)์˜ ์‹ค๋‚ด ์ˆ˜๋ฆฌ์‹คํ—˜ ์กฐ๊ฑด์„ ๋ฐ”ํƒ•์œผ๋กœ ์กฐ๋„๊ณ„์ˆ˜๋Š” 0.010์œผ๋กœ ์„ค์ •ํ•˜์˜€๋‹ค.

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Fig. 8. Velocity Comparisons Along the Transverse Sections of 90 Degree Curved Channel

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(a) Finite Elements and Flow Conditions

(b) Comparison of Velocities at Section 90 Degree Section According to mesh Resolutions

Fig. 9. Geometry, Finite Elements and Flow Conditions for 270 Degree Curved Channel

Fig. 10์— ๋งŒ๊ณก๋ถ€์—์„œ์˜ ์œ ์† ๋ฒกํ„ฐ๋„๋ฅผ ๋„์‹œํ•˜์˜€๋‹ค. ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•˜์ง€ ์•Š์€ ๊ฒฝ์šฐ ๋งŒ๊ณก์ด ์‹œ์ž‘๋˜๋Š” 0๋„๋ถ€ํ„ฐ ์ˆ˜๋กœ ๋‚ด์ธก์˜ ์œ ์†์ด ๋น ๋ฅด๊ฒŒ ๋ถ„ํฌํ•˜์—ฌ ๋งŒ๊ณก์ด ์ข…๋ฃŒ๋˜๋Š” 270๋„๊นŒ์ง€ ์ˆ˜๋กœ ์šฐ์ธก์˜ ์œ ์†์ด ๋น ๋ฅด๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๊ณ , ๊ณก์„ ๋ถ€ ์ข…๋ฃŒ ์ดํ›„๋ถ€ํ„ฐ ์ ์ฐจ ๊ท ์ผํ•œ ์œ ์†์ด ๋ถ„ํฌํ•จ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ๋ฐ˜๋ฉด ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๊ฒฝ์šฐ์—๋Š” ๋งŒ๊ณก๋ถ€ ์œ ์ž…์ง€์ ์ธ 0๋„ ์ดํ›„ ์ˆ˜๋กœ ๋‚ด์ธก์˜ ์œ ์†์ด ๋น ๋ฅด๊ฒŒ ๋‚˜ํƒ€๋‚ฌ์ง€๋งŒ, 90๋„ ์ง€์  ์ด์ „์— ๊ท ์ผํ•œ ์œ ์†์ด ๋ฐœ์ƒํ•˜์˜€๊ณ , ์ดํ›„๋ถ€ํ„ฐ๋Š” ์˜คํžˆ๋ ค ์ˆ˜๋กœ ์™ธ์ธก์˜ ์œ ์†์ด ๋น ๋ฅด๊ฒŒ ๋‚˜ํƒ€๋‚˜ ํ•˜๋ฅ˜๋‹จ๊นŒ์ง€ ๊ณ„์† ์ด์–ด์กŒ๋‹ค. Fig. 11์—๋Š” 270๋„์˜ ๋งŒ๊ณก๋ถ€๋ฅผ 4๋“ฑ๋ถ„ํ•˜๋Š” ์ธก์„ ์ธ 0๋„, 90๋„, 180๋„ ๋ฐ 270๋„ ์—์„œ์˜ ํšก๋ฐฉํ–ฅ ์œ ์†๋ถ„ํฌ๋ฅผ ์ˆ˜๋กํ•˜์˜€๋‹ค. ์ˆ˜๋กœ ์ขŒ์•ˆ์œผ๋กœ๋ถ€ํ„ฐ ๋‚ด์ธก ๋ฐฉํ–ฅ์œผ๋กœ์˜ ํšก๋ฐฉํ–ฅ ๊ฑฐ๋ฆฌ(y)๋ฅผ ์ˆ˜๋กœ ํญ(W)์œผ๋กœ ๋‚˜๋ˆ„์–ด ๋ฌด์ฐจ์›ํ™”(y/W)ํ•œ ๋ณ€์ˆ˜๋ฅผ ๊ฐ€๋กœ์ถ•์— ์‚ฌ์šฉํ•˜์˜€๊ณ , ์„ธ๋กœ์ถ•์€ ๋‹จ๋ฉดํ‰๊ท  ์œ ์†์œผ๋กœ ๋ฌด์ฐจ์›ํ™”ํ•œ ๊ฐ’์„ ์ด์šฉํ•˜์˜€๋‹ค. ๋งŒ๊ณก์ด ์‹œ์ž‘๋˜๋Š” 0๋„์—์„œ์˜ ํšก๋ฐฉํ–ฅ ์œ ์†๋ถ„ํฌ๋ฅผ ๋น„๊ตํ•œ Fig. 11(a)์—์„œ๋Š” ๋ถ„์‚ฐ์‘๋ ฅ์˜ ์œ ๋ฌด์— ๊ด€๊ณ„์—†์ด ์ˆ˜๋กœ ๋‚ด์ธก์˜ ์œ ์†์ด ๋‹ค์†Œ ๋†’๊ฒŒ ๋‚˜ํƒ€๋‚˜๋Š” ์œ ์‚ฌํ•œ ๊ฒฐ๊ณผ๋ฅผ ๋ณด์˜€๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๋ถ„์‚ฐ์‘๋ ฅ์„ ๋ฌด์‹œํ•œ ๊ฒฝ์šฐ์—๋Š” 90๋„์™€ 180๋„์—์„œ๋„ ์—ฌ์ „ํžˆ ์šฐ์•ˆ์ธก(y/W=1)์˜ ์œ ์†์ด ๋†’๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๋‹ค. ๋ฐ˜๋ฉด, ๋ถ„์‚ฐ์‘๋ ฅ์„ ๊ณ ๋ คํ•œ ๊ฒฝ์šฐ์—๋Š” 90๋„์—์„œ ์ˆ˜๋กœ ํญ์— ๊ฑธ์ณ ๊ฑฐ์˜ ๊ท ์ผํ•œ ์œ ์†์ด ๋ฐœ์ƒํ•˜์—ฌ Hicks ๋“ฑ(1990)์˜ ์ˆ˜๋ฆฌ์‹คํ—˜๊ฒฐ๊ณผ์™€ ๋ณด๋‹ค ๊ทผ์‚ฌํ•˜์˜€์œผ๋ฉฐ, 180๋„ ๋ฐ 270๋„ ์ธก์„ ์—์„œ๋„ 0 โ‰ค y/W โ‰ค 0.2์— ํ•ด๋‹นํ•˜๋Š” ์ˆ˜๋กœ ์™ธ์ธก์˜ ์œ ์†์ด ๋น ๋ฅด๊ฒŒ ๋‚˜ํƒ€๋‚˜ ๋ถ„์‚ฐ์‘๋ ฅ์ด ์—†๋Š” ์ˆ˜์น˜๋ชจ์˜ ๊ฒฐ๊ณผ์— ๋น„ํ•ด ์ˆ˜๋ฆฌ ์‹คํ—˜๊ฒฐ๊ณผ์™€ ์ž˜ ๊ทผ์‚ฌํ•˜์˜€๋‹ค. ํ•˜์ง€๋งŒ ๋‘ ๊ฒฐ๊ณผ ๋ชจ๋‘ 90๋„ ๋‹จ๋ฉด ์ดํ›„๋ถ€ํ„ฐ ์ˆ˜๋กœ ์šฐ์ธก ๋ฒฝ๋ฉด ๊ทผ์ฒ˜์—์„œ ์ˆ˜๋ฆฌ์‹คํ—˜ ๊ฒฐ๊ณผ์— ๋น„ํ•ด ์œ ์†์„ ๊ณผ๋Œ€ ์‚ฐ์ •ํ•˜์˜€๋‹ค. ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๊ฒฝ์šฐ์—๋„ ์›์‹ฌ๋ ฅ์— ์˜ํ•ด ํ๋ฆ„์ด ๊ฐ€์†๋˜๋Š” ๋ถ€๋ถ„์˜ ์œ ์†์€ ๋น„๊ต์  ์ž˜ ์˜ˆ์ธกํ•˜์˜€์ง€๋งŒ ๋ฐ˜๋Œ€์ธก ๋ฒฝ๋ฉด ๊ทผ์ฒ˜์—์„œ์˜ ์œ ์†์„ ๋‹ค์†Œ ๊ณผ๋Œ€ ์‚ฐ์ •ํ•˜์˜€๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•˜์ง€ ์•Š์€ ๊ฒฝ์šฐ์— ๋น„ํ•ด ํšก๋ฐฉํ–ฅ ์šด๋™๋Ÿ‰ ๋ถ„๋ฐฐ ๊ธฐ์ž‘์ด ์ž‘์šฉํ•˜์—ฌ ์šฐ์•ˆ์—์„œ์˜ ์œ ์†์„ ๊ณผ๋Œ€ ์‚ฐ์ •ํ•˜๋Š” ๊ฒƒ์„ ์ค„์ผ ์ˆ˜ ์žˆ์—ˆ๋‹ค. ๋ฒฝ๋ฉด ๊ฒฝ๊ณ„์กฐ๊ฑด์„ ๋ฌดํ™œ์กฐ๊ฑด์œผ๋กœ ๋ถ€์—ฌํ•˜์—ฌ ์ˆ˜์น˜๋ชจ์˜๋ฅผ ์ˆ˜ํ–‰ํ•œ ๊ฒฝ์šฐ ์ด์™€ ๊ฐ™์€ ํ˜„์ƒ์€ ๋ฐœ์ƒํ•˜์ง€ ์•Š์•˜์ง€๋งŒ, ์ˆ˜๋กœ ์ค‘์•™๋ถ€์—์„œ ์œ ์†์„ ๊ณผ๋Œ€ ์‚ฐ์ •ํ•˜๋Š” ๋‹จ์ ์ด ์žˆ์—ˆ๋‹ค. ์šด๋™๋Ÿ‰๋ฐฉ์ •์‹์— ํฌํ•จ๋œ ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์€ ์ƒ์„ฑ/์†Œ๋ฉธ๊ณผ ๊ฐ™์€ ์—ญํ• ์„ ํ•˜์—ฌ, ๋งŒ๊ณก์˜ ๋‚ด์ธก์—์„œ ์™ธ์ธก์œผ๋กœ ํšก๋ฐฉํ–ฅ ์šด๋™๋Ÿ‰์„ ์ด๋™์‹œํ‚ค๊ฒŒ ๋˜๋ฏ€๋กœ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•˜๋Š” ๊ฒฝ์šฐ ๋ณด๋‹ค ์ •ํ™•ํ•œ ์ˆ˜์น˜๋ชจ์˜ ๊ฒฐ๊ณผ๋ฅผ ์–ป์„ ์ˆ˜ ์žˆ์—ˆ๋‹ค.

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(a) Without Dispersion

(b) With Dispersion

Fig. 10. Velocity Vector for 270 Degree Curved Channel

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Fig. 11. Velocity Comparisons Along the Transverse Sections of 270 Degree Curved Channel

5. ๊ฒฐ ๋ก 

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” 3์ฐจ์› Reynolds ๋ฐฉ์ •์‹์„ ์ˆ˜์‹ฌ ์ ๋ถ„ํ•˜๋Š” ๊ณผ์ •์—์„œ ๊ท ์ผํ•œ ์œ ์†๋ถ„ํฌ๋ฅผ ๊ฐ€์ •ํ•˜์—ฌ ๋งŒ๊ณก๋ถ€์—์„œ ์ด์ฐจ๋ฅ˜๊ฐ€ ์ฃผ ํ๋ฆ„ ์œ ์†์— ๋ฏธ์น˜๋Š” ์ด์†ก์˜ ์˜ํ–ฅ์„ ๋ฌด์‹œํ•œ ๊ธฐ์กด ๋Œ€๋ถ€๋ถ„์˜ ์—ฐ๊ตฌ ๋ฐ ๋ชจํ˜•๊ณผ๋Š” ๋‹ฌ๋ฆฌ ์ข…ํšก๋ฐฉํ–ฅ ์œ ์†์˜ ์—ฐ์ง๋ถ„ํฌ๋ฅผ ํ‰๊ท ๊ฐ’๊ณผ ์ด๋กœ๋ถ€ํ„ฐ์˜ ๋ณ€๋™๋Ÿ‰์˜ ํ•ฉ์œผ๋กœ ์ •์˜ํ•˜๊ณ , ์ด ๊ฐ’๋“ค์„ ์šด๋™๋Ÿ‰๋ฐฉ์ •์‹์— ๋Œ€์ž…ํ•˜์—ฌ ์ƒ์„ฑ๋˜๋Š” ์ถ”๊ฐ€์ ์ธ ํ•ญ์ธ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•˜๋Š” ์ˆ˜์น˜๋ชจํ˜•์„ ๊ฐœ๋ฐœํ•˜์˜€๋‹ค. ์œ ์†๋ถ„ํฌ์— ๋Œ€ํ•œ ์ˆ˜ํ•™์  ๋ชจํ˜•์œผ๋กœ๋Š” ํƒ„ํƒ„ํ•œ ์ด๋ก ์  ๊ธฐ๋ฐ˜์„ ๊ฐ€์ง€๊ณ  ์žˆ์œผ๋ฉฐ, ๋ฐ”๋‹ฅ์—์„œ์˜ ๋ฌดํ™œ์กฐ๊ฑด์„ ์ž˜ ๋งŒ์กฑ์‹œํ‚ค๊ณ , ๊ธฐ์กด์˜ ์‹คํ—˜๊ฒฐ๊ณผ์™€๋„ ์ž˜ ์ผ์น˜ํ•˜๋Š” ์žฅ์ ์ด ์žˆ๋Š” de Vriend(1977)์˜ ์ œ์•ˆ์‹์„ ์ด์šฉํ•˜์˜€๋‹ค.

์ œ์•ˆ๋œ ๋ชจํ˜•์„ 30๋„, 90๋„, 270๋„์˜ ๊ณก๋ฅ ์„ ๊ฐ€์ง€๋Š” ์ˆ˜๋กœ์— ์ ์šฉํ•˜์—ฌ ๋ชจ์˜๊ฒฐ๊ณผ๋ฅผ ์ˆ˜๋ฆฌ์‹คํ—˜ ๊ฒฐ๊ณผ ๋ฐ ํƒ€ ์ˆ˜์น˜๋ชจํ˜• ๋ชจ์˜ ๊ฒฐ๊ณผ์™€ ๋น„๊ตํ•˜์˜€๋‹ค. 30๋„ ๊ณก์„ ์ˆ˜๋กœ ๋ชจ์˜ ๊ฒฐ๊ณผ, STREMR ๋ชจํ˜•(Bernard์™€ Schneider, 1992)์˜ ๊ฒฝ์šฐ ์ด์ฐจ๋ฅ˜์˜ ์˜ํ–ฅ์„ ๋‹จ์ˆœํžˆ ์œ ์„ ๋ฐฉํ–ฅ ์™€๋„์— ๊ด€ํ•œ ๊ฒฝํ—˜ ์ด์†ก์‹์— ์˜ํ•ด ๊ณ„์‚ฐํ•˜์—ฌ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๋ณธ ๋ชจํ˜•์— ๋น„ํ•ด ๋งŒ๊ณก๋ถ€์—์„œ ํ๋ฆ„์ด ์™ธ์ธก์œผ๋กœ ํŽธํ–ฅ๋˜๋Š” ์œ ์†๊ตฌ์กฐ๋ฅผ ์˜ฌ๋ฐ”๋ฅด๊ฒŒ ๋ฐ˜์˜ํ•˜์ง€ ๋ชปํ•˜์˜€์œผ๋ฉฐ, 90๋„ ๊ณก์„ ์ˆ˜๋กœ ๋ชจ์˜ ๊ฒฐ๊ณผ ๋ถ„์‚ฐ์‘๋ ฅ์„ ๋ฌด์‹œํ•œ ๊ฒฝ์šฐ ์ˆ˜๋กœ ๋‚ด์ธก์—์„œ๋Š” ์œ ์†์ด ๋‚ฎ๊ฒŒ ๋‚˜ํƒ€๋‚˜๊ณ  ์™ธ์ธก์—์„œ๋Š” ๋†’๊ฒŒ ๋‚˜ํƒ€๋‚˜ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๊ฒฝ์šฐ์— ๋น„ํ•ด ์œ ์† ๊ฒฝ์‚ฌ๊ฐ€ ์™„๋งŒํ•˜๊ฒŒ ๋ถ„ํฌํ•˜์˜€๋‹ค. 270๋„ ๊ณก์„ ์ˆ˜๋กœ ๋ชจ์˜ ๊ฒฐ๊ณผ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•˜์ง€ ์•Š์€ ๊ฒฝ์šฐ ๋งŒ๊ณก์ด ์‹œ์ž‘๋˜๋Š” 0๋„๋ถ€ํ„ฐ ๋งŒ๊ณก์ด ์ข…๋ฃŒ๋˜๋Š” 270๋„๊นŒ์ง€ ์ˆ˜๋กœ ๋‚ด์ธก์˜ ์œ ์†์ด ๋น ๋ฅด๊ฒŒ ๋‚˜ํƒ€๋‚ฌ๊ณ , ๊ณก์„ ๋ถ€ ์ข…๋ฃŒ ์ดํ›„๋ถ€ํ„ฐ ์ ์ฐจ ๊ท ์ผํ•œ ์œ ์†์ด ๋ถ„ํฌํ•˜์˜€์œผ๋‚˜, ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•œ ๊ฒฝ์šฐ์—๋Š” ๋งŒ๊ณก๋ถ€ ์œ ์ž…์ง€์ ์ธ 0๋„ ์ดํ›„ ์ˆ˜๋กœ ๋‚ด์ธก์˜ ์œ ์†์ด ๋น ๋ฅด๊ฒŒ ๋‚˜ํƒ€๋‚ฌ์ง€๋งŒ, 90๋„์ง€์  ์ด์ „์— ๊ท ์ผํ•œ ์œ ์†์ด ๋ฐœ์ƒํ•˜์˜€๊ณ , ์ดํ›„๋ถ€ํ„ฐ๋Š” ์˜คํžˆ๋ ค ์ˆ˜๋กœ ์™ธ์ธก์˜ ์œ ์†์ด ๋น ๋ฅด๊ฒŒ ๋‚˜ํƒ€๋‚˜ ํ•˜๋ฅ˜๋‹จ๊นŒ์ง€ ๊ณ„์† ์ด์–ด์ ธ์„œ ์ˆ˜๋ฆฌ์‹คํ—˜๊ฒฐ๊ณผ์™€ ๊ทผ์‚ฌํ•˜์˜€๋‹ค. ๋ณธ ์—ฐ๊ตฌ์˜ ์ˆ˜์น˜๋ชจ์˜ ๊ฒฐ๊ณผ, ์šด๋™๋Ÿ‰๋ฐฉ์ •์‹์— ํฌํ•จ๋œ ๋ถ„์‚ฐ์‘๋ ฅํ•ญ์€ ์ƒ์„ฑ/์†Œ๋ฉธ๊ณผ ๊ฐ™์€ ์—ญํ• ์„ ํ•˜๋Š” ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋˜๋ฉฐ, ์ด๋Š” ๋งŒ๊ณก์˜ ๋‚ด์ธก์—์„œ ์™ธ์ธก์œผ๋กœ ํšก๋ฐฉํ–ฅ ์šด๋™๋Ÿ‰์„ ์ด๋™์‹œ์ผœ์„œ ๋ถ„์‚ฐ์‘๋ ฅ์„ ํฌํ•จํ•˜์ง€ ์•Š๋Š” ๊ฒฝ์šฐ๋ณด๋‹ค ์ •ํ™•ํ•œ ์ˆ˜์น˜๋ชจ์˜ ๊ฒฐ๊ณผ๋ฅผ ์ œ๊ณตํ•˜๋Š” ๊ฒƒ์œผ๋กœ ์‚ฌ๋ฃŒ๋œ๋‹ค.

Acknowledgements

๋ณธ ์—ฐ๊ตฌ๋Š” ๊ตญํ† ๊ตํ†ต๋ถ€ ๊ฑด์„ค๊ตํ†ต๊ธฐ์ˆ ์ด‰์ง„์—ฐ๊ตฌ์‚ฌ์—… ๊ธฐ์ˆ ์‚ฌ์—…ํ™” ๊ณผ์ œ์™€ ๊ฑด์„ค๊ธฐ์ˆ ํ˜์‹ ์‚ฌ์—…(11๊ธฐ์ˆ ํ˜์‹ C06)์˜ ์—ฐ๊ตฌ๋น„์ง€์›์— ์˜ํ•ด ์ˆ˜ํ–‰๋˜์—ˆ์Šต๋‹ˆ๋‹ค. ๋ณธ ์—ฐ๊ตฌ๋Š” ์„œ์šธ๋Œ€ํ•™๊ต ๊ณตํ•™์—ฐ๊ตฌ์†Œ ๋ฐ ๊ฑด์„คํ™˜๊ฒฝ์ข…ํ•ฉ์—ฐ๊ตฌ์†Œ์˜ ์ง€์›์œผ๋กœ ์ˆ˜ํ–‰๋˜์—ˆ์Šต๋‹ˆ๋‹ค.

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