Experimental and Computational Studies of Jet Fuel Flow near the Freeze Point

• Published in: Journal of propulsion and power 2006-05, Vol.22 (3), p.534-541, Article 534
• Main Authors: Assudani, Rajee, Ervin, Jamie S, Zabarnick, Steven, Shafer, Linda
• Format: Article
• Language: English
• Subjects: Jet engine fuels
• ISSN: 0748-4658; 1533-3876
• DOI: 10.2514/1.16423

To study the flow behavior of jet fuel at low temperatures, a wing-tank thermal simulator, which represents the fuel tank of a commercial aircraft, was fabricated. The simulator was subjected to cooling in an environmental chamber. Experimental results show that fuel flowability and pumpability decrease substantially as temperature is reduced. Time-dependent temperature and velocity distributions were numerically simulated for static cooling. Viscosities were obtained from viscometer measurements using different jet fuel samples. It was observed that near the freeze-point temperature, low freeze-point fuels tend to have higher viscosities than high freeze-point fuels. Measured viscosities were used in computational-fluid-dynamics simulations of jet fuel that was cooled. The calculations show that stringers, ribs, and other structures strongly promote fuel cooling. Also, the cooler, denser fuel resides near the bottom surface of the fuel tank simulator. The presence of an ullage space within the tank was found to strongly influence the fuel temperature profile by sometimes reducing cooling from the upper surface. In other instances, the tillage space enhanced cooling.