A survey on moving mass control technology

A review of parametric approaches specific to aerodynamic design process

A layered fluctuation model of electron density in plasma sheath and instability effect on electromagnetic wave at Ka band

A new set of generalized transport equations is derived for higher-order moments which are generated in evolution equation for stress tensor and heat flux vector in 13-moment equations. The closure we employ satisfies Onsager's symmetry principle. In the derivation, we do not employ a phase density function based on Hermite polynomial series in terms of higher-order moments, unlike Grad's approach. The distribution function is rather chosen to satisfy collision invariance, and H-theorem and capture relatively strong deviations from equilibrium. The phase density function satisfies the linearized Boltzmann equation and provides the correct value of the Prandtl number for monatomic gas. The derived equations are compared with Grad's 13-moments equations for gas modeled as Maxwellian molecule. The merits of the proposed equations against Grad's and R13 equations are discussed. In particular, it is noted that the proposed equations contain higher-order terms compared to these equations but require a fewer number of boundary conditions as compared to the R13 equations. The Knudsen number envelope which can be covered to describe flows with these equations is therefore expected to be larger as compared to the earlier equations.

Onsager's-principle-consistent 13-moment transport equations.

Recent advances in contact dynamics and post-capture control for combined spacecraft

Analysis of weakly ionized ablation plasma flows for a hypersonic vehicle

Formulation of a new set of Simplified Conventional Burnett equations for computation of rarefied hypersonic flows

The linear Navier–Stokes–Fourier (NSF) constitutive relations are derived on the assumption of the small deviation from local thermodynamic equilibrium, and consequently they may fail in describing...

Computation of Hypersonic Flows over Flying Configurations Using a Nonlinear Constitutive Model

Non-equilibrium effects exist extensively in microfluidic flows, and the accurate simulation of the Knudsen layer behind them is rather challenging for the linear Newton–Fourier model. In this paper, a high-order reduced model (nonlinear coupled constitutive relations) from Eu’s generalized hydrodynamic equations is applied for the investigation of the micro-Couette flows of diatomic nitrogen and monatomic argon as well as Maxwell and hard-sphere molecules using the MacCormack scheme. In order to simulate the confined flows accurately, a set of enhanced wall boundary conditions based on this model are derived with respect to the degree of non-equilibrium. Both the 1st-order Maxwell–Smoluchowski model and the Langmuir slip model are also investigated. For a large range of Knudsen numbers, the results show that the enhanced boundary conditions make a significant improvement in the prediction of flow profiles, especially the temperature profile. The reason behind that is analyzed in detail. The numerical predictions obtained from the high-order model in conjunction with the enhanced boundary conditions are also compared with DSMC, regularized 13 moment equations, Burnett-type equations as well as Navier–Stokes solutions, which highlight its excellent capability in describing the underlying mechanism of the Knudsen layer in the Couette flow.

Numerical analysis of the micro-Couette flow using a non-Newton–Fourier model with enhanced wall boundary conditions

A new method for calibrating a parallel robot is proposed as part of a project aimed at developing a calibration method for spacecraft docking mechanism motion simulator. To implement this method, a calibration equation is built by generating the constraint conditions of the end-effector's motion in the workspace using a three-dimensional coordinate measuring machine. According to the established calibration equation and the simulation, the geometrical parameters of the parallel robot are identified. The effectiveness of the calibration method with a coordinate measuring machine is verified through random pose test experiment.

https://journals.sagepub.com/doi/pdf/10.5772/45684

Weifang Chen

Papers

Analysis of weakly ionized ablation plasma flows for a hypersonic vehicle

Formulation of a new set of Simplified Conventional Burnett equations for computation of rarefied hypersonic flows

Computation of Hypersonic Flows over Flying Configurations Using a Nonlinear Constitutive Model

Numerical analysis of the micro-Couette flow using a non-Newton–Fourier model with enhanced wall boundary conditions

Kinematic Calibration of Parallel Robots for Docking Mechanism Motion Simulation