Hierarchical Progressive Optimization for Aerodynamic/Stealth Conceptual Design Based on Generalized Parametric Modelling and Sensitivity Analysis

A hierarchical progressive optimization approach is proposed for multidisciplinary optimal design by integrating with generalized parametric modeling and sensitivity analysis. The framework includes the following: (1) to set up a generalized parametric model for the geometric parameters of flight vehicles with different levels, (2) to reduce the number of design parameters using sensitivity analysis method and (3) to use the gradual optimization design method to solve the problem of integrated aerodynamic-stealth optimization design. The results from the application on the configuration optimization of an aircraft demonstrate that the hierarchical progressive optimization increases the fitness of the optimization design by 51.1% and improves the conceptual design efficiency

Modeling and Analysis of Fluid-Thermal-Structure Coupling Problems for Hypersonic Vehicles

To efficiently model fluid-thermal-structural problems for thermal protection design of hypersonic vehicles, a framework of Hypersonic Computational Coupling Dynamics (HyCCD) software integrates an independently developed program solving hypersonic aerthermodynamic simulation with a finite element analysis professional software. With the mathematical and physical description of multi-physics coupling mechanism, the corresponding efficient coupling strategies were proposed. Some representative coupling problems encountered in hypersonic vehicle were systematically analyzed to study the intrinsic fluid-thermal-structural coupling characteristics and mechanisms. The results can theoretically and technically support the studies on comprehensive performance assessment and optimization of thermal protection system and static or dynamic aerothermoelastic problem of hypersonic vehicles

Fabrication and Characterization of Composite Containing HCl-Doped Polyaniline and Fe Nanoparticles

HCl-doped polyaniline powder (HCl-PANI) was synthesized by using a polymerization procedure. Fe nanoparticles were then deposited on the HCl-PANI at room temperature by direct current magnetron sputtering. After this process the HCl-PANI-Fe composite was obtained. Fe nanoparticle size in the composite is about 100 nm. HCl-PANI structure is not influenced by the Fe nanoparticles. The composite pellet has room temperature ferromagnetism and a conductivity of 0.25 S/cm. Temperature dependence of the conductivity reveals that a carrier transport mechanism in the composite is three-dimensional variable range hopping. Thermogravimetric analysis reveals that a weight loss of the HCl-PANI-Fe composite is smaller than that of the HCl-PANI for the same heating temperature when the temperature exceeds 230°C

1-(3-Pyrid­yl)pyrrolidine-2,5-dione

In the title mol­ecule, C9H8N2O2, the dihedral angle between the pyridine and the pyrrolidine rings is 64.58 (12)°. In the crystal structure, weak C—H⋯π-electron ring inter­actions stabilize the packing