AIAA Journal

An experimental study was conducted on a NACA 0025 airfoil at [Formula: see text] to investigate the interaction between disparate forcing frequencies on separation control and coherent flow dynamics. Using a dual-row microblower array, forcing frequencies were set to [Formula: see text] and [Formula: see text] at two distinct chordwise locations. While single-row low-frequency forcing promotes l…

A subsonic, axisymmetric, internally mixed jet exhibited powerful, periodic self-sustained oscillations and tonal acoustic emissions of the same frequency when the bypass stream was operated at a lower pressure ratio than the core stream. Experimental acoustic and flow measurements with unheated and heated flow were collected for two mixing-duct lengths. It was found that, in all cases, the oscil…

In upcoming missions to the moon, transporting as much payload as possible within a limited timeframe is a critical challenge. However, identifying an optimal spacecraft system design is complex due to the interdependence of multiple subsystems, each requiring distinct design methodologies. Multidisciplinary design optimization (MDO), which concurrently evaluates various disciplines to identify a…

Modularly assembled tensegrity structures represent a promising paradigm for future large-scale space infrastructure, where tailorable dynamic performance is essential for mission-critical applications. However, conventional hexagonal prism tensegrity systems suffer from insufficient structural stiffness, limiting their practical utility. This study introduces a cable-reinforced hexagonal prism t…

This study comprehensively and systematically investigates the universality of the normalized, steady, laminar heat flux distribution over a hypersonic sphere, an important topic of both fundamental and practical relevance. Utilizing an extensive dataset of 70 Navier–Stokes simulations, the analysis encompasses a wide range of freestream conditions, gas models, boundary-layer thicknesses, sphere …

This study investigates the multiscale complexity and wave-number partitioning of airfoil boundary-layer fluctuating pressures measured in the NF-3 wind tunnel at Northwestern Polytechnical University. A multifractal asymmetric correction model is established. The energy cascade characteristics of transition and turbulence are studied via proper orthogonal decomposition (POD). The results indicat…

Aircraft design involves optimization within extremely high-dimensional geometric design spaces, posing a fundamental challenge for aerodynamic shape optimization. Although geometric filtering has improved design-space compactness compared to conventional parameterization methods, a compelling need remains to further shrink the design space without sacrificing design quality. This study introduce…

With the rapid development of infrared detection and guidance technology, future fighter aircraft will face the search and detection of enemy aerial, air and ground all-round infrared detection systems. To determine the average infrared radiation intensity in the rear hemisphere of straight flow exhaust systems, an approximate calculation method was designed basing on limited data. This method wa…

To address the excessive model order issue in flexible multibody spacecraft dynamic models developed using the hybrid coordinate method, this paper presents a model order reduction algorithm that achieves dimensionality reduction through selective mode shape prioritization and weighted synthesis. First, a multibody dynamic model for a spacecraft with a central rigid body and flexible appendages i…

Multifidelity uncertainty propagation combines the efficiency of low-fidelity models with the accuracy of a high-fidelity model to construct statistical estimators of quantities of interest. It is well known that the effectiveness of such methods depends crucially on the relative correlations and computational costs of the available computational models. However, the question of how to automatica…

Compressible Navier–Stokes simulations have been performed to study the laminar near-wake of two-dimensional adiabatic hypersonic blunt bodies. In particular, the modified free-interaction theory from previous work has been examined for cylindrical geometries with a truncated aftbody of finite shoulder radius. The geometries investigated were a single-parameter family of geometries based on the r…

Periodic unsteady flow problems often exhibit computational inefficiency when conventional time-domain methods are employed. This phenomenon can be attributed to the lengthy transition phase before reaching the ultimate periodic state. To address this problem, the harmonic balance method (HBM) is employed for aeroacoustic applications through the implementation of convective monopole sources, fre…

Artificial intelligence (AI) and machine learning (ML) have profoundly revolutionized the aviation industry, and researchers are increasingly prioritizing these new technologies in various applications. However, the traditional end-to-end (E2E) neural networks suffer from insufficient feature extraction from single-source input data, which limits the model’s performance. To overcome this drawback…

A numerical analysis of boundary-layer stability over the cone–cylinder–flare geometry is conducted at Mach 6 and a Reynolds number of [Formula: see text] in order to investigate the role of wall-to-recovery temperature ratio similarity in hypersonic boundary-layer transition. The study compares typical flight conditions with wind-tunnel experiments to assess differences caused by the missing wal…

Helicopter fuselage vibration is mainly caused by rotor excitation loads. Active vibration control (AVC) has become an effective means to reduce helicopter fuselage vibration. The higher harmonic control (HHC) algorithm in the frequency domain has been widely used in AVC due to advantages such as simplicity, strong robustness, and ease of implementation. However, HHC has drawbacks such as long up…

The aeroelastic behavior of insect-inspired flexible flapping wings (FFWs) directly dictates flight performance and is critical for the efficient operation of FFW-based aerial vehicles. However, most existing FFW models fail to simultaneously account for coupled twisting and bending, limiting their ability to accurately capture how leading-edge (LE) local flexibility affects aerodynamics. To addr…

Shock wave interference is a common phenomenon in hypersonic vehicles. It modifies the load distribution across the wing surface, thereby affecting the aeroelastic characteristics. This paper investigates the influence of shock wave interference location and intensity on the flutter characteristics of a hypersonic airfoil using a method based on a reduced-order model. The flutter mechanism under …