DOI QR코드

DOI QR Code

Numerical Analysis for Improvement of Windshield Defrost Performance of Electric Vehicle

전기자동차 전면유리 제상성능 개선을 위한 전산수치 해석

  • Kim, Hyun-Il (Corporation Support Department, Pohang Institute of Metal Industry Advancement) ;
  • Kim, Jae-Sung (Industry-University Cooperation Foundation, Hanbat National University) ;
  • Kim, Myung-Il (Supercomputing Modeling & Simulation Center, Korea Institute of Science and Technology Information) ;
  • Lee, Jae Yeol (Industrial Engineering, Chonnam National University)
  • 김현일 (포항금속소재진흥원 기술지원실) ;
  • 김재성 (한밭대학교 산학협력단) ;
  • 김명일 (한국과학기술정보연구원 가상설계센터) ;
  • 이재열 (전남대학교 산업공학과)
  • Received : 2019.02.08
  • Accepted : 2019.05.03
  • Published : 2019.05.31

Abstract

As the residence time in the vehicle increases, the passenger desires a pleasant and stable riding environment in addition to the high driving performance of the vehicle. The windshield defrosting performance is one of the performance requirements that is essential for driver's safe driving. In order to improve the defrosting performance of the windshield of a vehicle, relevant elements such as the shape of the defrost nozzle should be appropriately designed. In this paper, CFD based numerical analysis is conducted to improve defrost performance of small electric vehicles. The defrost performance analysis was performed by changing the angle of the defrost nozzle and the guide vane that spray hot air to the windshield of the vehicle. Numerical simulation results show that the defrosting performance is best when the defrost nozzle angle is $70^{\circ}$ and the guide vane installation angle is $60^{\circ}$. Based on the analytical results, the defrosting experiment was performed by fabricating the defrost nozzle and the guide vane. As a result of the experiment, it is confirmed that the frost of windshield is removed by 80% within 20 minutes, and it is judged that the defrost performance satisfying the FVMSS 103 specification is secured.

차량에 거주하는 시간이 증가하면서 탑승자는 차량의 높은 주행성능과 더불어 쾌적하고 안정성 높은 승차 환경을 원하고 있다. 자동차 전면유리 제상성능은 운전자의 안전운전을 위해 필수적으로 요구되는 성능 중 하나이다. 자동차의 전면유리의 성에 제거 성능을 향상시키기 위해서는 제상 노즐의 형상과 같은 관련 요소들을 적절하게 설계하여야 한다. 본 논문에서는 소형 전기자동차의 제상성능 개선을 위하여 CFD 기반의 전산수치해석을 수행하였다. 자동차 전면유리에 뜨거운 공기를 분사하는 제상 노즐과 가이드 베인의 각도를 변경하면서 제상 성능해석을 수행하였다. 전산수치해석 결과, 제상노즐 각도 $70^{\circ}$ 및 가이드 베인 설치 각도 $60^{\circ}$인 경우가 가장 우수한 제상성능을 보이는 것으로 분석되었다. 해석결과를 바탕으로 제상노즐과 가이드 베인을 제작하여 제상실험을 수행하였으며, 해석결과와 실험결과가 매우 유사함을 확인할 수 있었다. 또한 실험결과, 자동차 전면유리의 성에가 20분 이내 80% 제거됨을 확인 할 수 있어, FVMSS 103 규정을 만족하는 제상성능을 확보한 것으로 판단된다.

Keywords

SHGSCZ_2019_v20n5_477_f0001.png 이미지

Fig. 1. The electric vehicle used in numerical analysis and experiment

SHGSCZ_2019_v20n5_477_f0002.png 이미지

Fig. 2. Defrost nozzle analysis model (a) Frost , glass and defrost nozzle (b) Defrost nozzle angle

SHGSCZ_2019_v20n5_477_f0003.png 이미지

Fig. 3. Analysis model for Defrost nozzle with guide vane (a) Guide vane (b) Guide vane angle

SHGSCZ_2019_v20n5_477_f0004.png 이미지

Fig. 4. Analysis result of the defrost nozzle angle (70°) (a) Velocity vector (b) Temperature distribution

SHGSCZ_2019_v20n5_477_f0005.png 이미지

Fig. 5. Analysis result of defrost nozzle angle(70°) and guide vane angle(50°) (a) Velocity vector (b) Temperature distribution

SHGSCZ_2019_v20n5_477_f0006.png 이미지

Fig. 6. Analysis result of defrost nozzle angle(70°) and guide vane angle(60°) (a) Velocity vector (b) Temperature distribution

SHGSCZ_2019_v20n5_477_f0007.png 이미지

Fig. 7. Experimental defrost nozzle

SHGSCZ_2019_v20n5_477_f0008.png 이미지

Fig. 8. Comparison of defrost analysis and experiment

SHGSCZ_2019_v20n5_477_f0009.png 이미지

Fig. 9. FMVSS 103 specification and defrost experiment (a) Typical location of vision area as viewed from interior of vehicle (b) Defrost experiment result of Area C

Table 1. Initial and boundary condition

SHGSCZ_2019_v20n5_477_t0001.png 이미지

Table 2. Air density according to temperature

SHGSCZ_2019_v20n5_477_t0002.png 이미지

Table 3. Material property of windshield

SHGSCZ_2019_v20n5_477_t0003.png 이미지

Table 4. Material property of frost

SHGSCZ_2019_v20n5_477_t0004.png 이미지

Table 5. Summary of average temperature and velocity according to the nozzle angle

SHGSCZ_2019_v20n5_477_t0005.png 이미지

Table 6. Summary of average temperature and velocity according to the nozzle and guide vane angle

SHGSCZ_2019_v20n5_477_t0006.png 이미지

References

  1. H. H. Jeon, S. B. Ko and K. B. Lee, "A Numerical Study on Automobile Interior Environment" Korean Journal of Air-conditioning and refrigeration engineering, Vol.19, No.1, pp. 36-42, 2007.
  2. S. J. Kang, Y. D. Jun and K. B. Lee, "A Numerical Study of a Vehicle Windshield Defrosting Mechanism", Journal of Energy Engineering , Vol. 19, No. 3, pp. 151-155, 2010.
  3. S. N. Patil, P. D. Sonawane, "Survey on Recent trends in Computational & Experimental Technique to Evaluate Performance of Air Flow in Defrost/Demist System for Automobile" Int. J. of Engineering and Computer Science, Vol.3, No.7, pp. 6859-6862, 2014
  4. S. H. Kang, J.H. Lee and J.S. Byun, "3D Unsteady Numerical Analysis to Design Defrosting System of Automotive Windshield Glass", Transactions of KSAE, Vol. 15, No. 5, pp.1-8, 2007.
  5. Y. M Youn, F. Kader, Kum-Bae Lee and Yong-Du Jun, "Numerical Study on Control Factors of Defrosting Performance for Automobile Windshield Glass in Winter", Kor. J. Air-Cond. Refrig. Eng., Vol. 20, No.12, pp. 789-794, 2008.
  6. D. J. Kim and J. K. Lee, "Effects of an Inlet Guide Vane on the Flowrate Distribution Characteristics of the Nozzle Exit in a Defrost Duct System", Transactions of KSAE, Vol. 16, No. 4, pp.88-96, 2008.
  7. D. J. Kim, H. J. Kim, J. K. Lee and B. J. Rho, "An Experimental Study on the Flow Characteristics with the Impinging Angles of Defrost Nozzle Jet Inside a Vehicle Passenger Compartment", The Korean Society of Mechanical Engineers, Vol. 31(12), pp.1024-1032, 2007. https://doi.org/10.3795/KSME-B.2007.31.12.1024