Unsteady aerodynamic prediction is an important part of modern aircraft safety and control law design. To improve the accuracy efficiency for unsteady at high angles attack, this paper proposed a machine learning framework based on multifidelity methods. The combines linear dynamic derivative model fuzzy neural network model, which can achieve higher under sparse experimental states. A series wind-tunnel tests was carried out pitching motions NASA Common Research Model to obtain steady...

An improved delayed detached eddy simulation (IDDES) method based on the k-ω-SST (shear stress transport) turbulence model was applied to predict unsteady vortex breakdown past an 80°/65° double-delta wing (DDW), where angles of attack (AOAs) range from 30° 40°. Firstly, IDDES and relative numerical methods were validated by simulating massively separated flow around NACA0021 straight at AOA 60°. The fluctuation properties lift pressure coefficients analyzed compared with available...

This paper focuses on the design of a disturbance rejection controller for tailless aircraft based technique nonlinear dynamic inversion (NDI). The model mounted three degree-of-freedom (3-DOF) rig in wind tunnel is modeled as affine system subject to mismatched disturbances. First all, baseline NDI attitude designed sufficient stability and good reference tracking performance nominal system. Then, observer (NDO) supplemented estimate lumped disturbances compensation, including unmodeled...

Post-stall maneuverability is a key technical indicator for modern fighter. It requires fighter to maintain excellent dynamic behaviors at high angle of attack. The stability derivative design input off light control system and one its important sources the wind tunnel test. In order meet stricter quality requirements test data, China Aerodynamics Research & Development Center (CARDC) has set up forced oscillation based on single degree freedom in open section Φ3.2 m tunnel. Based...

Single-based propellants containing 0.4wt%, 0.8wt% and 1.6wt% nickel powders(NPs) were prepared investigated in closed bomb tester transparent combustion chamber, which can provide variable-pressure constant-pressure conditions for propellant burning, respectively. In tester, burned to a pressure above 5-220MPa. The results showed that burning rate of was increased by 19.0%, 12.5% 11.9% 5-8MPa, 8-16MPa 20-200MPa, when NPs used propellant. Meanwhile, chamber with constant 1.0MPa, 1.5MPa,...

Tailless aircraft suffers from limited yaw control power and poor directional stability inherently.To address these issues in the early design process of a tailless configuration with low costs risks, this paper presents an innovative experimental approach to law validation quantitative flying quality evaluation dynamically scaled model mounted on three degree-of-freedom rig wind tunnel.The motion equations demonstrator are derived, then comparisons lateral-directional flight dynamics...

The pilot-in-loop real-time simulation platform has been designed to address the challenges associated with wind tunnel free-flight test. In this paper, test facility is briefly described, an emphasis on design, development and verification of platform. And a detailed description its hardware software architecture, subsystem design implementation flight procedure given. Finally, paper makes comparison study between results results, verify its' succeed in overcoming experimental pilots...

DEGDN propellant plays an important role in the use of large-caliber artillery, and its combustion mechanical properties determine power artillery. In order to study performance propellant, four kinds single-hole with different pore diameters were prepared from raw material ZY-11 pellets, 3mm, 4mm, 5mm, 6mm, which recorded as 45/1-3mm, 45/1-4mm, 45/1-5mm, 45/1-6mm, respectively. Analyze using closed bomb test impact resistance a pendulum tester. The experimental results show that process,...

Loss-of-control has become the largest fatal accident category for worldwide commercial jet accidents, and any initiative aimed at preventing such events requires an understanding of fundamental aircraft behavior, especially flight dynamics post-stall region which loss-of-control usually occurred. A series low-speed static dynamic wind tunnel tests Common Research Model over a large angle attack/sideslip envelope was conducted non-linear aerodynamic model developed. The bifurcation analysis,...

The thermal decomposition of RDX-based propellants with different RDX contents (40, 30, and 10 wt%) was characterized by high-pressure differential scanning calorimetry at 0.1, 2.0, 4.0 MPa. activation energy solid pressures calculated using the Friedman-Reich-Levi, ASTM E698, Flynn-Wall-Ozawa methods, kinetic parameters were isoconversional methods. results showed that curves 40 30 wt% presented a double peak. second peak more obvious an increase in content. With pressure, temperature...

Abstract Taking a medium and large caliber high chamber pressure gun as the object single charge an example, optimization design model of propellant was established by using theory, trajectory parameters 100mm were optimized, optimal scheme satisfying constraints is obtained. The results this paper have some guiding significance for gun.

Inert gas was added to a gun-launched missile chamber eliminate the flammability hazard of residual propellant gases. The combustible contents three types propellants were calculated using constitution model. Based upon this information, gases analyzed. Considering CO2 as fully reacted and assuming composition does not change during mixing process with product gases, quantities required mixture nonflammable one obtained. This information helps solve practical engineering problems.