In this study, velocity distribution characteristics by location and uniformity according to exit straight length in a 180° mixed pipes were numerically analyzed using RSM (Reynolds Stress Model) turbulent model by changing various flow parameters such as working fluids, inlet air velocity etc. As a result of it, the working fluids characteristics was highly indicated by the viscous force difference, the maximum velocity points according to main pipe’s inlet velocity were indicated when 90° sectional location was distributed at X/D=0.5~0.6 region and 180° sectional location was distributed at Y/D=0.5 region. And the flow characteristics according to branch pipe’s inlet velocity when 90° sectional location was distributed at X/D=0.4~0.6 region and 180° sectional location was distributed at Y/D=0.5 region. Based on the results that the most stable exit straight length in flow uniformity was indicated at L/D=25~30 region, 40D is suggested as the effective measurement distance in the straight pipe downstream curved pipe of mixed pipe.

ABSTRACT
 1. 서 론
 2. 수치해석
  2.1 해석모델
  2.2 수치해석
 3. 결과 및 고찰
  3.1 난류모델의 타당성 검증
  3.2 작동유체에 따른 유동특성
  3.3 주배관의 입구속도에 따른 유동특성
  3.4 분기관의 입구속도에 따른 유동특성
  4.3 곡관후류 직관부에서 유동속도의 균일도 특성
 4. 결 론
 References

• 이형민(Graduate student of Mechanical Engineering Department, Gachon Univ.) | Hyung-Min Lee
• 김광추(Head of Mechanical Engineering Department, KEPCO-E&C) | Kwang-Chu Kim
• 임종한(Professor of Mechanical Engineering Department, Gachon Univ.) | Jong-Han Lim
• 윤준규(Department of Mechanical Engineering, Gachon University) | Jun-Kyu Yoon Corresponding Author