Convective heat transfer coefficient relating to evaluation of thermal environment of infant

Yoshihito Kurazumi; Kenta Fukagawa; Tomonori Sakoi; Ken Yamashita; Akie Naito; Motoe Imai; Yoshiaki Yamato; Emi Kondo; Tadahiro Tsuchikawa

doi:10.1016/j.heliyon.2022.e12076

Convective heat transfer coefficient relating to evaluation of thermal environment of infant

Heliyon. 2022 Dec 5;8(12):e12076. doi: 10.1016/j.heliyon.2022.e12076. eCollection 2022 Dec.

Authors

Yoshihito Kurazumi¹, Kenta Fukagawa², Tomonori Sakoi³, Ken Yamashita¹, Akie Naito⁴, Motoe Imai⁵, Yoshiaki Yamato⁶, Emi Kondo⁷, Tadahiro Tsuchikawa⁸

Affiliations

¹ School of Life Studies, Sugiyama Jogakuen University, Nagoya, Japan.
² Department of Environmental Science and Technology, Meijo University, Japan.
³ Department of Advanced Textile and Kansei Engineering, Shinshu University, Ueda, Japan.
⁴ Institute for Global Leadership, Ochanomizu University, Tokyo, Japan.
⁵ Graduate School of Life Studies, Sugiyama Jogakuen University, Nagoya, Japan.
⁶ Department of Architecture and Structural Engineering, Kure National College of Technology, Kure, Japan.
⁷ Department of Comprehensive Engineering, Kindai University Technical College, Nabari, Japan.
⁸ School of Human Science & Environment, University of Hyogo, Himeji, Japan.

Abstract

Infants have a low capacity to thermally adapt to their environment and so sufficient consideration must be given to their thermal environment. In investigating an infant's thermal environment, the purpose of this study is to clarify the heat transfer coefficient in natural convection for the posture of an infant in a stroller. The heat transfer coefficients were measured by means of using a thermal manikin. The experimental thermal environment conditions were set for eight cases, at: 16 °C, 18 °C, 20 °C, 22 °C, 24 °C, 26 °C, 28 °C, and 30 °C, and the air and wall surface temperatures were equalized, creating a homogeneous thermal environment. The air velocity (less than 0.2 m/s) and relative humidity (50%RH) were the same for each case. The surface temperature of each part of the thermal manikin was controlled to 34 °C. The difference between the mean surface temperature and air temperature (ΔT [K]) is the driving force for the heat transfer coefficient in natural convection for the posture of an infant in a stroller (h_c [W/(m²·K)]). We propose the use of the empirical formula h_c = 2.16 ΔT ⁰ ^.23. The formula of the convective heat transfer coefficient in natural convection of this study can be applied to infants up to about 3 years old.

Keywords: Heat transfer coefficient; Infant; Natural convection; Stroller; Thermal environment.