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In order to analyze the influence of the wake jet on the tail flow field during the take-off and landing phase of the aircraft, this paper uses Computational Fluid Dynamics technology, takes an aircraft as the research object, and uses the RANS equation, Realizable k-ε turbulence model and the Delaunay unstructured meshing method. The Roe discrete scheme is used to numerically simulate the wake field of the aircraft using the coupled implicit algorithm, which is divided into two conditions: wake jet and no wake jet. The simulation results show that there is a certain back pressure zone in the wake field of the aircraft, the gauge pressure range is -272∼1067 Pa, the pressure difference at the same position in the wake field area is small, the range is -240∼60 Pa, and the wake field pressure has little correlation with the wake jet, and there is no separation vortex under the two conditions. The simulation results verify the rationality and effectiveness of the simulation calculation, and provide a certain theoretical reference for the safe take-off and landing of the aircraft.

The K-G model has better practicability and superiority than the E-μ model. Conventional triaxial tests of frozen sand samples were carried out at -10 C under confining pressures of 0.5 MPa, 1.0 MPa, 2.0 MPa, 4.0 MPa and 6.0 MPa. During the consolidation process, the samples behave an isobaric state. While the confining pressure σ3 is unchanged, axial pressure σ1 is gradually increased during the shearing process. The test results show that the volumetric strain increases nonlinearly with the increase of the volumetric stress in the isobaric state, showing a power function trend. An improved K-G model is proposed to describe strain softening of frozen sand during shear. The verification results show that the model has good applicability.

With a view to the potential application on stealth design of inductively coupled plasma (ICP), the simulation model of ICP scattering parameters was established by using COMSOL and ZT-FDTD method. Some detail of the interaction between electromagnetic wave and plasma in time domain which was difficult to be observed in experiment was revealed in the simulation. Wave source points composed of continuous reflection waves in the plasma were observed. The position of the wave source depends on the spatial distribution of the electron density peak. The influence of gas pressure (10 mTorr~1 Torr) and power (300~700 W) on attenuation efficiency was studied. The wave attenuation in plasma is characterized by band attenuation. The attenuation significantly improved with the increase of pressure and thickness monotonically. As the power increased, both the band width and amplitude of wave attenuation increased.