Advances in Cryogenic Engineering pp 1297-1304 | Cite as

# Numerical Analysis of Heat Transport Mechanism in Nitrogen Near the Critical Point

## Abstract

A heat transport mechanism in nitrogen near the critical point is investigated by means of a numerical calculation. The thermofluid equations are solved by using the finite difference method. Calculations confirm a piston effect in nitrogen near the critical point. These results show that thin thermal boundary layers form near the walls while the remaining bulk fluid exhibits a uniform temperature distribution. This suggests a typical feature of the piston effect which is a relatively new mechanism of thermal energy transfer; i.e., the thermal energy propagates as acoustic waves rather than as heat conduction. The thermal boundary layers become thinner as the system approaches the critical point. The effect of gravity on the heat transport mechanism is also investigated in this report.

## Keywords

Critical Temperature Thermal Boundary Layer Isothermal Compressibility Supercritical State Heated Wall## Preview

Unable to display preview. Download preview PDF.

## References

- 1.Guenoun, P., Khalil, B., Beysens, D., Garrabos, Y., Kammoun, F., Neindre, B.L., and Zappoli, B., Thermal cycle around the critical point of carbon dioxide under reduced gravity, Phys. Rev. E, 47 (3) (1993) pp. 1531–1540CrossRefGoogle Scholar
- 2.Beysens, D., New critical phenomena observed under weightlessness, materials and fluids under low gravity, 464 (1995) pp. 3–25CrossRefGoogle Scholar
- 3.Straub, J., Eicher, L. and Haupt, A., Dynamic temperature propagation in a fluid near its critical point observed under microgravity during the german spacelab mission D-2, Phys. Rev. E, 51 (6) (1995) pp.5556–5563CrossRefGoogle Scholar
- 4.Onuki, A., Ferrell, R. A., Adiabatic heating effect near the gas-liquid critical point, Physica A, 164(1990) pp.245–264CrossRefGoogle Scholar
- 5.Zappoli, B., Amiroudine, S., Carles, P., Ouazzani, J., Numerical solutions of thermoacoustic and buoyancy-driven transport in near critical fluid, Materials and Fluids under Low Gravity, 464 (1995) pp.27–40CrossRefGoogle Scholar
- 6.Maekawa, T., Ishii, K., Temperature propagation in a single component critical fluid, Thermal Science and Eng. (The Heat Transfer Soc. of Japan), 5 (1) (1997) pp.15–23Google Scholar
- 7.Fletcher, C.A.J., Computational technique for fluid dynamics, Springer Verlag (1988)CrossRefGoogle Scholar
- 8.Voronel, A. V., Gorbunova, V. G., Chashkin, Yu. R, and Shchekochikhina V. V., Specific heat of nitrogen near the critical point, Sov. Phys. JETP, 23 (1966) pp.597–601Google Scholar
- 9.Basu, R. S., Sengers, J. V., Viscosity of nitrogen near critical point, J. of Heat Transfer, 101 (1979)pp.3–8Google Scholar
- 10.Ziebland, H., and Burton, J. T. A., The thermal conductivity of nitrogen and argon in the liquid and gaseous state, British J. of Appied Phys., 9 (1958) pp 52–59CrossRefGoogle Scholar
- 11.Pestak, M. W. and Chan, M. H. W., Equation of state of N2 and Ne near their critical points. scaling, corrections to scaling, and amplitude ratios, Physical Rev. B, 30 (1) (1984) pp.274–288CrossRefGoogle Scholar