Effect of wall conduction on the heat transfer characteristics of supercritical n-decane in a horizontal rectangular pipe for cooling of a scramjet combustor

Abstract

<jats:sec> <jats:title content-type="abstract-subheading">Purpose</jats:title> <jats:p>The purpose of this paper is to numerically study the influence of wall conduction on the heat transfer of supercritical n-decane in the active regenerative cooling channels.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Design/methodology/approach</jats:title> <jats:p>A horizontally placed rectangular pipe with a solid zone and another one without a solid zone were used. A drastic variation of thermo-physical properties was emphatically addressed. After the verification of mesh and turbulence models comparing with the experimental results, a mesh number of 4.5 M and the low Reynolds number SST k-ω turbulence model were chosen. The solution of the governing equations and the acquisition of the numerical results were executed by the commercial software FLUENT 2020 R1.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Findings</jats:title> <jats:p>The numerical results indicate that there is a heat transfer deterioration (HTD) potential for the upper wall, lower wall and sidewall with the decrease of mass flux. Due to wall conduction, the distribution of the fluid temperature at spanwise-normal planes becomes uniform and this feature also takes advantage of the relatively uniform transverse velocity. For the streamwise-normal planes, the low fluid temperature appears close to the upper wall at the region near the sidewall and vice versa for the region near the centre. Undoubtedly, the secondary flow at the cross-section plays a crucial role in this process and the relatively cool mainstream is affected by the vortices.</jats:p> </jats:sec> <jats:sec> <jats:title content-type="abstract-subheading">Originality/value</jats:title> <jats:p>This study warns that the wall conduction must be considered in the practical design and thermal optimization due to the sensibility of thermo-physical properties to the heat flux. The secondary flow caused by the buoyancy force (gravity) plays a significant role in the supercritical heat transfer and mixed convection heat transfer should be further studied.</jats:p> </jats:sec>

Research status of supercritical aviation kerosene and a convection heat transfer considering thermal pyrolysis

“…The scramjet engine can provide effective thrust for hypersonic vehicles (Sunden et al , 2016; Li et al , 2021a). However, thermal protection is an extremely crucial issue due to supersonic combustion and aerodynamic heating (Pizzarelli et al , 2016; Daniau et al , 2005).…”

Uncertainty Quantification of GEKO Model Coefficients on Compressible Flows

“…Brezgin and Aronson adjusted the value of C SEP for the sensitivity regarding adverse pressure gradients and spreading rates, which were overpredicted by conventional models (standard k-ω, SST k-ω) [8]. Additionally, Li et al [9] compared the GEKO model with other turbulence models to investigate the influence of wall conduction on the heat transfer of supercritical n-decane in active regenerative cooling channels.…”