Thermal performance of automotive radiators made of plastic and stainless steel microtubes

Thermal performance of automotive radiators made of plastic and stainless steel microtubes

Článek WoS

The thermal performance of low-temperature radiators constructed from staggered banks of stainless steel microtubes (SST unit) and polymeric fibers (PF unit, polyamide 612) was investigated in air cross-flow conditions. Tests were performed in a calorimetric wind tunnel according to automotive standards with air velocities of 2-10 m/s and coolant flow rates of 6-60 l/min. Experimental results demonstrated that airside pressure drops for SST and PF radiators are nearly identical, with a difference of approximately 1 %, showing that tube material did not influence airside pressure drops. Regardless of the 50-time difference in thermal conductivity between stainless steel (12 W/(m & sdot;K)) and polyamide (0.24 W/(m & sdot;K)), the heat transfer rate of the PF radiator was, on average, only 7 % lower than ST, with smaller deviations observed at lower air velocities. The Gaddis and Gnielinski model showed good prediction, with average discrepancies of 3 % for heat transfer rate, 7 % for overall and airside heat transfer coefficients, and 5 % for pressure drops. The results confirm that, when middle buffers are used, polymeric hollow-fiber radiators can be a viable lightweight alternative to metals for low-to-moderate airflow applications (2-10 m/s air speed).

The thermal performance of low-temperature radiators constructed from staggered banks of stainless steel microtubes (SST unit) and polymeric fibers (PF unit, polyamide 612) was investigated in air cross-flow conditions. Tests were performed in a calorimetric wind tunnel according to automotive standards with air velocities of 2-10 m/s and coolant flow rates of 6-60 l/min. Experimental results demonstrated that airside pressure drops for SST and PF radiators are nearly identical, with a difference of approximately 1 %, showing that tube material did not influence airside pressure drops. Regardless of the 50-time difference in thermal conductivity between stainless steel (12 W/(m & sdot;K)) and polyamide (0.24 W/(m & sdot;K)), the heat transfer rate of the PF radiator was, on average, only 7 % lower than ST, with smaller deviations observed at lower air velocities. The Gaddis and Gnielinski model showed good prediction, with average discrepancies of 3 % for heat transfer rate, 7 % for overall and airside heat transfer coefficients, and 5 % for pressure drops. The results confirm that, when middle buffers are used, polymeric hollow-fiber radiators can be a viable lightweight alternative to metals for low-to-moderate airflow applications (2-10 m/s air speed).

Plastic heat exchanger; Staggered tube bank; Air cross flow; Heat transfer coefficient, Pressure drop; Microtube radiator

Plastic heat exchanger; Staggered tube bank; Air cross flow; Heat transfer coefficient, Pressure drop; Microtube radiator

ASTROUSKI, I.; BOHÁČEK, J.; MRÁZ, K.; HORÁK, A.; BARTULI, E.

2026

01.02.2026

Elsevier

Case Studies in Thermal Engineering

78

February

Nizozemsko

1

12

12

https://www.sciencedirect.com/science/article/pii/S2214157X26000432

http://hdl.handle.net/11012/256332