Koolnapadol, N., Sripattanapipat, S., & Skullong, S. (2018). Effect of pitch spring of delta-winglets on thermal characteristics in a heat exchanger tube. Journal of Research and Applications in Mechanical Engineering, 4(2), 166–174. Retrieved from https://ph01.tci-thaijo.org/index.php/jrame/article/view/138646