30 results about "Velocity equation" patented technology

The invention relates to a circuit modeling and simulation method representing the terahertz quantum cascading laser device multimode effect. The method includes the steps of firstly, establishing a multimode velocity equation set representing carrier transportation characteristics inside a THzQCL active layer; secondly, establishing a physical equation model representing the multimode effect inside the THzQCL; thirdly, obtaining a corresponding equivalent circuit model through variable substitution and simplification; fourthly, establishing an equivalent circuit model representing the electrical characteristics of the input end of the THzQCL; fifthly, establishing an equivalent circuit model representing the luminous power characteristics of the output end of the THzQCL; sixthly, establishing a circuit macro model which comprises an electrical port and an optical power output port, and conducting photoelectric property simulation and output spectral property testing on the basis of the circuit macro model. By means of the circuit modeling and simulation method, the influences of the temperature on various photoelectric properties of the THzQCL can be tested, and imitation and simulation for the photoelectric property and the output multimode effect of the THzQCL can be supported and achieved.

The invention relates to a flight icing numerical value simulation method of a helicopter rotor wing. The flight icing numerical value simulation method is mainly characterized by comprising the following steps that: a vorticity compensation force algorithm is added into a momentum equation and an energy equation in a single fluid model used for vortex movement used for simulating air-super cold water drop two-phase flows under a rotating coordinate system in rotor wing trail traces, and a centrifugal force and geostrophic force algorithm is added into a super cold water drop sliding velocity equation; a water film movement and icing model of the centrifugal force and the geostrophic force is considered; and the algorithms and the models are used for carrying out the flight icing numerical value simulation flow process of the helicopter rotor wing, wherein the model of single fluid two-phase flowing used for simulating the simulating air-super cold water drop movement is realized by a partial differential equation group for describing the movement of air and air-super cold water drop binary mixtures in a rotor wing tail trace flow field, and a two-phase flow slipping speed model. The condition that the quality and energy changes are generated in water films and ice layers because of the rotary movement of the rotor wing is considered in the model of the water film movement and icing process on the rotor wing surface, and the icing shape of the rotor wing surface is obtained.

The invention relates to a projectile nutation angle extraction method based on radar Doppler data. The method is characterized by comprising the following specific steps of arranging a radar tail chasing distributed station at the side rear part of an artillery or a rocket artillery, carrying out tracking measurement on a flying artillery shell or a rocket artillery shell, and estimating the radial velocity of a centroid; calculating micro motion speeds; extracting a precession period; resolving a velocity vector; calculating the nutation angle of a projectile. According to the method, the difficult problem in nutation angle measurement of the flying projectile under the conditions of long distance is solved effectively, and the motion of the rotating projectile in the air includes micro motions relative to the centroid, such as precession and nutation, besides centroid motion; radar signals are subjected to periodic modulation, namely micro-Doppler effect, by the micro motions. Internal data of the radial velocity obtained through radar measurement contain information on the micro motions, such as nutation, a nutation angle curve of the projectile can be obtained through processing the internal data, and the nutation angle of the projectile is obtained through an established micro-motion velocity equation.

A robust control method for angular speed stability of an under-actuated spacecraft aims at the under-actuated spacecraft with two thrusters, and the angular speed stability control law having robustness for generalized model errors of a system is designed. First a system model comprising the generalized model errors is established, and a system dynamics equation comprising the generalized model errors such as system inertia uncertainty, executing mechanism installing errors and angular speed measuring errors is obtained. Then the robust control method aiming at the derived system is designed, and global asymptotic stability is proved. Finally, a conception of a homogeneous system is introduced, and the fact that the control law enables the global asymptotic stability of an original system is analyzed and proved. The method provides a theory basis for the under-actuated spacecraft for practical engineering application, and the control law is simple in form. The robust control method can be used for robust control for angular speed stability of various under-actuated spacecrafts for which the thrusters are adopted.

The invention provides a method for quantitatively inverting porosity by using seismic wave impedance and belongs to the field of exploration and development of oil and gas. The method comprises the following steps: taking the seismic wave impedance as input data, constructing an error function inverting the porosity by using a rock physical equation and a seismic wave propagation velocity equation, constructing a feasible domain space of solutions in the value range of the porosity, and performing iterative inversion in the feasible domain space by adopting a non-linear global optimization algorithm to obtain the final porosity. The method provided by the invention is based on the rock physical equation and an elastic parameter to invert the seismic porosity, so that the physical significance is clear and the applicability is strong; the value range of the porosity is added into the inversion process as a constraint, so that the stability and the prevision in inversion are improved, and the advantage of prestack elastic parameter inversion can be kept; moreover, the method has the advantage of directly forecasting an oil and gas distribution favorable zone and can be directly used for inverting the porosity of actual seismic data.