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The process of obtaining flight data from flight test is complex and costly, which makes it difficult to identify aerodynamic parameters. Therefore, Cessna172 flight simulator was used for flight data extraction, which ensures the convenience, efficiency and economy of the test. To obtain aerodynamic model, based on the idea of machine learning, a recurrent neural network was used to process multi-dimensional nonlinear flight test data, and a real-time recursive learning algorithm was proved to be suitable for dynamic training. Due to the large amount of state parameter data generated by aircraft, which will cause the real-time recursive learning algorithm to train slowly. So, Kalman filter algorithm was introduced for system identification. Considering validity analysis, the comparative verification method was used to verify system identification model. Results show that the aircraft aerodynamic and aerodynamic moment models have good applicability and can be popularized and applied.

The plate-fin heat exchanger has been widely applied in the field of air separation and aerospace due to its high specific surface area of heat transfer. However, the low heat transfer efficiency of its plate bundles has also attracted more attention. It is of great significance to optimize the structure of plate-fin heat exchanger to improve its heat transfer efficiency. The plate bundle was studied by combining numerical simulation with experiment. Firstly, according to the heat and mass transfer theory, the plate bundle calculation model of plate-fin heat exchanger was established, and the accuracy of the UDF (User-Defined Functions) for describing the mass and heat transfer was verified. Then, the influences of fin structure parameters on the heat and mass transfer characteristics of channel were discussed, including the height, spacing, thickness and length of fins. Finally the influence of various factors on the flow field performance under different flow states was integrated to complete the optimal design of the plate bundle.

Inlet is the key part which can influence the performance of airframe-propulsion integration for the air-breathing vehicle. In supersonic or hypersonic condition, the local vibration of the structure will change the integrated performance greatly. The work is to study the influence of the structural vibration of the compression surface on the inlet’s performance, and the vibration factors such as amplitude, wavelength and frequency are evaluated. The influence of the vibration factors on the inlet’s performance is studied. The research shows that the structure of the flow field for the inlet is changed. The influence is more obvious when the vibration occurs to be more closed to the lip. Besides, the wavelength has more influence than the amplitude, and the influence of the frequency is smallest.

The cavity is widely used in the advanced flight vehicle. However, there are also some new aerodynamic characteristic when cavity is exposed in high-speed flow. The flow characteristic of high-speed cavity is studied in this paper based on detached-eddy simulation method. The M219 cavity benchmark under transonic flow is used as the validation case for numerical methods and grid strategy. Comparison of predicted sound pressure levels and spectra against the wind tunnel experiment has proved that the numerical methods capture the major oscillation dynamics inside the cavity. The aerodynamic characteristic of cavity with a store is investigated in this paper, there are three vortexes in the cavity and the main vortex in the middle rotates around the store. The shear layer breaks earlier compared with clean cavity due to the turbulent flow around the store. However, the small store has little influence to the sound pressure level of cavity.

A numerical study on supersonic cavity flow is carried out, where the influence law of the freestream parameters and configuration factors on static aerodynamic characteristics is investigated, focusing on the change of pressure distribution on the cavity walls at high and low Mach numbers. It is found that with the Mach number increment at high speeds (M>2), the pressure peak on the rear side of the cavity bottom floor rises, and the change in pressure distribution on the cavity walls shows a variating trend in flow type from a closed-cavity flow to an open-cavity flow, which is consistent with the law at low speeds (M≤2). At high speeds, the change in Reynolds number has a certain impact on the pressure distribution in the cavity, which is inconsistent with the law at low speeds. The increase of Reynolds number will increase the pressure on the rear side of the cavity bottom floor and on the rear wall, and the greater the Mach number, the greater the difference caused by Reynolds number variation. When the length-to-depth ratio increases at high speeds, the pressure peak on the rear side of the cavity bottom floor decreases, and the flow type is changing from an open-cavity flow to a transitional-cavity flow, which is consistent with the law at low Mach numbers, while the pressure variation is greater at high speeds. The influence of the length-to-width ratio on the pressure distribution is relatively small, and the increase of length-to-width ratio increases the pressure peak on the rear side of the cavity bottom floor slightly. Spanwise bending has a certain impact on the pressure distribution. The pressure peak on rear side of the bottom floor increases when the cavity is bending, which is consistent with the influence caused by length-to-width ratio increment.

The stage separation of high-speed vehicle is complicated at high dynamic pressure, usually accompanied by strong shock and vortex interaction. There exists a strong interaction between first stage and second stage, which called “afterbody-effects”. The aerodynamic mechanism of “afterbody-effects” is studied in this paper based on numerical simulation. The aerodynamic characteristics of a simplified three-dimensional projectile model at different distances between stages at 0° angle of attack is researched with structural mesh. The results show that the vortexes of stages have a significant impact on the aerodynamic characteristics of different stages, As the distance between stages increases, the drag coefficient of the first stage increases, and the drag coefficient of the second stage increases first and then decreases.