Does the corrugated surface of corrugated radiator tubes in automotive components help improve the temperature uniformity of the heat dissipation surface?
Publish Time: 2025-09-08
In automotive thermal management systems, heat dissipation efficiency depends not only on the amount of heat exchange but also on the uniformity of temperature distribution on the heat dissipation surface. Localized overheating accelerates material aging, reduces coolant life, and can even trigger thermal runaway in electronic components or battery modules. Therefore, achieving uniform temperature on the heat dissipation surface is a key issue in improving system reliability and energy efficiency. Corrugated radiator tubes, with their unique corrugated surface structure, are widely used in components such as engine water tanks, intercoolers, motor coolers, and liquid cooling plates for power batteries.
1. Disturbing the flow field and eliminating localized "hot spots"
In traditional smooth straight tubes, the cooling medium easily forms a stable laminar boundary layer as it flows along the tube wall. This leads to intense heat transfer near the inlet region, while downstream, due to increased fluid temperature and a smaller temperature difference, heat transfer weakens, resulting in a large temperature gradient along the tube and uneven temperature distribution on the tube wall. The periodic undulating structure of the corrugated radiator tube continuously disturbs the fluid, disrupting boundary layer stability and promoting lateral mixing and secondary flow between crests and troughs. This enhanced convection effect allows heat to be transferred more evenly from the tube wall to the fluid core, significantly reducing temperature differences along the tube length and preventing the formation of localized "hot spots."
2. Increased Effective Heat Transfer Area and Balanced Heat Flux Density
The corrugated surface provides a larger actual heat transfer area for the same axial length. More importantly, this area gain is not concentrated at a single point but is uniformly distributed along the entire tube length. When high-temperature components contact the corrugated tube through the heat-conducting interface, the larger contact area means a lower heat flux density per unit area, thus slowing down the local temperature rise rate. Simultaneously, the corrugated structure allows heat to diffuse laterally along the tube wall more quickly, preventing heat accumulation at contact points and further promoting a more uniform surface temperature.
3. Promotes Turbulence Development and Improves Overall Thermal Response Consistency
The corrugated structure also promotes the earlier transition of the fluid from laminar to turbulent flow. Turbulence has a strong mixing effect, rapidly mixing high-temperature and low-temperature fluids to bring the fluid outlet temperature closer to the average value. This means that in multi-channel parallel radiators, the fluid temperature rise within each bellows is more similar, reducing temperature differences between channels caused by uneven flow distribution. This characteristic is particularly important for temperature-sensitive applications such as battery packs—typically requiring inter-module temperature differences to be controlled within 5°C, a requirement more easily met by liquid cooling systems using bellows.
In addition to the fluid-side advantages, the geometric flexibility of the bellows itself also contributes to temperature uniformity. During thermal cycling, thermal stress is generated due to differences in the coefficients of thermal expansion of materials. Smooth straight pipes have high rigidity, easily leading to stress concentration at weld points or connections, resulting in microcracks and affecting heat transfer continuity. Bellows structures, however, have a certain degree of axial and radial elasticity, absorbing some thermal deformation, reducing local stress peaks, and maintaining good contact between the pipe wall and the heat source, thus ensuring stable temperature distribution during long-term operation.
In summary, the corrugated surface of the corrugated radiator tube in automotive components not only improves overall heat exchange efficiency but also effectively enhances the temperature uniformity of the heat dissipation surface through multiple mechanisms, including flow field disturbance, area expansion, turbulence promotion, and stress buffering. In the context of electrification and high power density trends, this characteristic is irreplaceable in ensuring the safety and lifespan of critical components.
