The aerodynamic noise of an aircraft leads to vibration fatigue damage to structures. Herein, a prediction method for aircraft surface noise under the comprehensive effect of mixed acoustic sources during flight, primarily surface aerodynamic, air intake, and tail nozzle jet noises, was studied. In the supersonic cruising state, the internal and external flow fields of the aircraft were solved using the Reynolds-averaged Navier–Stokes equations to obtain the statistical average solution of the initial turbulence. The non-linear disturbance equation was used to obtain the surface acoustic load of the aircraft. The calculation results revealed that the main source of aircraft surface noise is aerodynamic noise. The sound pressure level on the fuselage increases gradually from front to rear along the aircraft, and the OASPL at the air intake and tail nozzle is relatively large. The jet noise has little effect on the sound pressure level at the front of the fuselage and only contributes to the OASPL at the tail nozzle of the fuselage. The intensity of pressure pulsations from the engine exhaust in the tail section is 93.3% of the total intensity of pressure pulsations.

Transonic buffet not only influences the structural integrity, handling quality and ride comfort, but also limits the flight envelope of transporters and airliners. To delay buffet onset and alleviate the buffet load, the effects of both steady and periodic tangential slot blowing are investigated. The results show that steady tangential blowing on the airfoil upper surface can postpone the buffet onset margin and evidently increase the lift coefficient at incidence angles near and above the buffet onset case of the clean airfoil. Under buffeting conditions of the clean airfoil, unsteady aerodynamic loads can be greatly suppressed by both steady and periodic blowing. The control effort is depicted as reduced wedge effect and weakened dynamic effect. The buffet mechanism includes (a) the feedback loop between the Kutta wave and the separation bubble under the shock foot, and (b) the interaction between the shear layer shed by the shockwave and Kutta waves. Under blowing conditions, the upstream creeping Kutta waves are prevented, and the intensity of the shear layer shed by the shockwave into separated flows is evidently reduced. Parametric studies show that the control effect is reduced as the blowing slot moves downstream, and steady blowing at 41% x/c is the most favorable control case.

Wind tunnel tests on the rigid model of large‐span shallow spherical shell roof structure were carried out. The variation rule and the calculation method for the average shape coefficient of the fluctuating wind pressure under six different typical wind directions were obtained. The wind pressure distribution of the node deflection and cross section stress was numerically investigated and analyzed. Meanwhile, the effect of mechanics‐flow form of the typical spherical shell structure on the wind pressure distribution was analyzed quantitatively. In this study, it is found that the results of numerical simulation agree well with the wind tunnel test data. The study on the mechanical characteristics, as well as the wind vibration research, of the spherical shell structure in different working conditions provides a reliable theoretical basis for the mechanical index of the wind vibration.

This study proposes a design method based on adjoint shape optimization to enhance the heat transfer efficiency of shell-and-tube heat exchangers in oil and gas transportation systems. The primary focus of this work is the design optimization of shell-and-tube heat exchangers through geometric optimization. By simplifying the complex three-dimensional shell-and-tube heat exchanger into a pseudo-three-dimensional reduced-order model, two-dimensional adjoint shape optimization analyses were conducted under unidirectional symmetry about the x-axis and bidirectional symmetry in the x- and y-axes, respectively. The optimized two-dimensional models exhibited a significant increase in the average outlet temperature. Furthermore, the optimized two-dimensional shapes were extruded and reconstructed into three-dimensional models for validation. The results demonstrate that the average air outlet temperature of the three-dimensional models increased by 5.35 K and 3.07 K compared to the original design. Flow field analysis revealed that the heat transfer was improved, since the optimized pipeline layout enhances flow separation and turbulent mixing, leading to a more uniform temperature distribution. This study validates the effectiveness of the adjoint shape optimization method in improving the performance of shell-and-tube heat exchangers.