Numerical simulation of surface pressure fluctuations in transonic fence-like flows with high Reynolds number

• Numerical simulation of loads relevant to the aircraft and aerospace industry.
• Simulations are compared to already existing measurements at high Re and Ma numbers.
• Spectral, correlation, mean and r.m.s. properties of the load is investigated.
• The aim is to determine the load for a response prediction of the exposed structure.
• Load CSD predictions are sufficient for a response prediction of an exposed panel.

Surface pressure fluctuations downstream of an inclined fence are investigated with compressible, large-eddy simulations with wall-treatment. The simulations are performed at Reh=1.6·106Reh=1.6·106 and transonic Mach numbers, which are realistic operating conditions in the aircraft industry. Simulation results are compared with existing measurements. Three different configurations are simulated to investigate the sensitivity to geometrical effects. Simulated cross-correlation spectra agreement with measurements appears to be on the level required for a good response prediction of an aircraft skin surface panel placed downstream of the fence. Root-mean-square pressure fluctuation levels are found to be closer to backward-facing step flow than standard fence flow. The effect of a leading edge upstream of the fence is shown to influence the spectral characteristics of the pressure load downstream of the fence. Correlation lengths and the propagation of pressure disturbances are investigated with auto and cross-correlation maps, phase angle analysis of the cross spectrum and frequency–wave-number spectra.