This paper proposes an explicit dynamic DDA method considering contact force, which aims at solving the problems of low efficiency detection and simulation force in conventional method. The mutual between blocks can be regarded as application point loading on a single block, corresponding submatrix calculated simultaneous equations block system integrated. central difference is adopted to deduce expression displacement containing force. With relationship constraint are obtained calculate...

The wind tunnel experiments was conducted to get inspiration for understanding the mechanism of asymmetric flow pattern and developing an innovative control technique a slender body at high angle attack. bi-stable situation side forces observed which could be easily switched by tiny disturbances either from coming or artificial nose tip (including manufacturing defect). In turbulent flows randomly between positive negative. There existed hysteresis loop force with rolling angle. A rod in...

The wind tunnel experiments is conducted to get inspiration for understanding the mechanism of asymmetric flow pattern and developing an innovative control technique a slender body at high angle attack. bi-stable situation side forces observed, which could be easily switched by tiny disturbances either from coming or artificial nose tip (including manufacturing defect). In turbulent flows randomly between positive negative. There exists hysteresis loop force with rolling angle. A rod in...

This paper proposes an improved DDA method based on explicitly solving contact constraints. The potential energy function generated by contacting, which contains only displacement variables as unknown, is deduced the approximated step and Lagrange interpolation, constraints are obtained via variable metric analyzing extremum. There no need to conduct open-close iteration during process of calculation. has high precision a more stable robust computational convergence. accuracy iterative...

The wind tunnel experiments for high angle of attack aerodynamics were designed from the inspiration understanding mechanism and development an innovative flow control technique. side force, varying with different rolling angle, is featured by bi-stable situation, can be easily switched a tiny disturbance. A miniature strake attached to nose tip model. When stationary, direction force controlled. strake, as unsteady means, swung pattern could results obtained dynamic measurements section...

In order to extract global skin friction from the evolution image of fluorescence oil-film, fluorescent oil film equation is introduced. On basis this theory, method for solving oil-film derived Horn & Schunk's optical flow technology and variational method. By means numerical simulation, verified. Finally, through study inclined impinging jet, application prospect in specific experiments demonstrated.