Disclosed is a method for evaluating computational fluid dynamic simulation results. The method includes, based on a set of initial conditions, performing a first baseline run and a second baseline run of a simulated area or volume containing a vehicle body shape, and then performing a change run of the simulated area or volume containing a modified vehicle body shape, and performing the following actions within the simulated area or volume: plotting an iso line of the first baseline run and a corresponding iso line of the second baseline run, plotting an iso line of the change run that corresponds to the iso line of the two baseline runs, and comparing whether the iso line of the change run falls between the iso lines of the two basline runs. If not, then the modification to the vehicle body shape may be considered significant.

A wind tunnel sting comprising a support member and a wind tunnel sting damper. The support member having a first support-member end configured for coupling with a wind tunnel, and a second support-member end configured for coupling with a balance. The wind tunnel sting damper having a reactive member, and a viscoelastic member disposed between the reactive member and the support member wherein, the reactive member is sized relative to the support member so as to radially compress the viscoelastic member against the support member.

A wind tunnel sting comprising a support member and a wind tunnel sting damper. The support member having a first support-member end configured for coupling with a wind tunnel, and a second support-member end configured for coupling with a balance. The wind tunnel sting damper having a reactive member, and a viscoelastic member disposed between the reactive member and the support member wherein, the reactive member is sized relative to the support member so as to radially compress the viscoelastic member against the support member.

A flight vehicle attitude control system design device includes: a gain calculator calculating a proportional gain and a derivative gain from a system natural frequency and a system damping coefficient; a margin calculator calculating a gain margin and a phase margin from the proportional gain and the derivative gain; a grid generator generating a gain-phase margin grid from a relationship between the proportional gain and the derivative gain and a relationship between the gain margin and the phase margin; and a display unit outputting the gain-phase margin grid on a control gain design region having a gain margin as one of a horizontal coordinate axis and a vertical coordinate axis and a phase margin as the other one of the horizontal coordinate axis and the vertical coordinate axis.

A flight vehicle attitude control system design device includes: a gain calculator calculating a proportional gain and a derivative gain from a system natural frequency and a system damping coefficient; a margin calculator calculating a gain margin and a phase margin from the proportional gain and the derivative gain; a grid generator generating a gain-phase margin grid from a relationship between the proportional gain and the derivative gain and a relationship between the gain margin and the phase margin; and a display unit outputting the gain-phase margin grid on a control gain design region having a gain margin as one of a horizontal coordinate axis and a vertical coordinate axis and a phase margin as the other one of the horizontal coordinate axis and the vertical coordinate axis.

A multi-dimensional vibration control method based on piezoelectric ceramic actuator applied to wind tunnel test of aircraft model. The pitch and yaw acceleration sensors arranged on the center of mass of the aircraft model are used to measure the two components of the main vibration acceleration of the aircraft model, and the main vibration vector of the aircraft model is obtained and the real-time vibration plane of the strut is determined. Inertia is introduced to solve the dynamic bending moment on the active section of the multi-dimensional vibration damper, and then the stress distribution on the active section is obtained. The multi-dimensional active vibration control system is adopted to improve the stability and reliability of the active vibration control system of wind tunnel model, extend the service life of piezoelectric ceramic actuator, and ensure the quality of wind tunnel test data and the safety of wind tunnel test.

Method for identifying slow transient variations and/or local spatial variations in vehicle related fluid dynamic conditions of a physical property in a set of data points. The method includes obtaining a first set of data points, calculating a temporal filtered value of the representation of the physical property for at least a portion of the first set of data points distributed over the total time period, combining at least a portion of the calculated temporal filtered values to obtain a second set of data points, and analysing in time sequence the second set of data points over at least a portion of the total time period.

An experimental setup for bridge deck large-amplitude vertical-torsional coupled free vibration in wind tunnel test, which belongs to the technical field of wind tunnel test apparatus. The experimental setup includes the rigid model, the rigid circular rods, the lightweight rigid circular sprockets, the chains, the linear tensile vertical springs, the bearings, the sliders, and the guides. For the new setup, large-amplitude vertical-torsional coupled free vibration of a rigid deck model that failed in conventional testing device can be adapted by the vertical deformation of the springs without any lateral tilt. As a result, the possible nonlinear mechanical stiffness due to the springs tilt in conventional testing device is excluded. In addition, owing to the low rolling friction and damping between the sprockets and the chains, the mechanical damping ratio of the system are quite low and stable for very large-amplitude vibrations.

An experimental setup for bridge deck large-amplitude vertical-torsional coupled free vibration in wind tunnel test, which belongs to the technical field of wind tunnel test apparatus. The experimental setup includes the rigid model, the rigid circular rods, the lightweight rigid circular sprockets, the chains, the linear tensile vertical springs, the bearings, the sliders, and the guides. For the new setup, large-amplitude vertical-torsional coupled free vibration of a rigid deck model that failed in conventional testing device can be adapted by the vertical deformation of the springs without any lateral tilt. As a result, the possible nonlinear mechanical stiffness due to the springs tilt in conventional testing device is excluded. In addition, owing to the low rolling friction and damping between the sprockets and the chains, the mechanical damping ratio of the system are quite low and stable for very large-amplitude vibrations.

Radiation curable compositions for additive fabrication processes, the components cured therefrom, and their use in particle image velocimetry testing methods are described and claimed herein. Such compositions include compounds which induce free-radical polymerization, optionally compounds which induce cationic polymerization, a filler constituent, and a light absorbing component, wherein the compositions are configured to possess certain absorbance values at wavelengths commonly utilized in particle image velocimetry testing. In another embodiment, the compositions include a fluoroantimony-modified compound. Such compositions may be used in particle imaging velocimetry testing methods, wherein the test object utilized is created via additive fabrication and is of a substantially homogeneous construction.