Flow and heat transfer characteristic of regenerative cooling channels using supercritical CO2 with circular tetrahedral lattice structures
Supercritical CO2 (sCO2) with its excellent heat and mass transfer capabilities is a promising substance to use in regenerative cooling of a scramjet at high Mach numbers (Ma ≥8). In combination with circular tetrahedral lattice (CTL) structures, this work investigates regenerative cooling channels...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-07-01
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| Series: | Case Studies in Thermal Engineering |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214157X25004642 |
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| Summary: | Supercritical CO2 (sCO2) with its excellent heat and mass transfer capabilities is a promising substance to use in regenerative cooling of a scramjet at high Mach numbers (Ma ≥8). In combination with circular tetrahedral lattice (CTL) structures, this work investigates regenerative cooling channels using sCO2 as an additional coolant. Using the SST k-ω turbulence model, the numerical study evaluates the flow and thermohydraulic performance of sCO2 in CTL channels under a heat load ranging from 1.5 MW to 6 MW, considering effects of blocking ratios and channel materials. The CTL structure enhances heat transfer by generating strong flow impingement, transverse secondary flows, corner vortices, flow re-attachment on the bottom wall which breaks up the thermal boundary layers. The temperature change in the axial and height directions of the channel is more gradual while the velocity distribution is optimized. At the blocking ratio of 8 %, the maximum wall temperature of the CTL channel is 52.5 % lower than that of the smooth channel. With increased blocking ratios (8 %–52 %) of CTL structures, normalized Nusselt number and overall thermal performance exhibit increasing trends ranging from 3.78 to 11.49 and from 1.52 to 2.65, respectively, although the Fanning friction factor is also quickly increasing from 0.58 to 3.27. Using a channel material with high thermal conductivity can significantly increase the equivalent heat transfer coefficients with the conjugated heat transfer model. Specifically, when Cu is used as the channel material, the overall thermal performance is 3.24 times higher than that of steel. |
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| ISSN: | 2214-157X |