The waveform of the explosion shock wave under free-field air explosion is an extremely complex problem.It is generally considered that the waveform consists of overpressure peak,positive pressure zone and negative pr...The waveform of the explosion shock wave under free-field air explosion is an extremely complex problem.It is generally considered that the waveform consists of overpressure peak,positive pressure zone and negative pressure zone.Most of current practice usually considers only the positive pressure.Many empirical relations are available to predict overpressure peak,the positive pressure action time and pressure decay law.However,there are few models that can predict the whole waveform.The whole process of explosion shock wave overpressure,which was expressed as the product of the three factor functions of peak,attenuation and oscillation,was proposed in the present work.According to the principle of explosion similarity,the scaled parameters were introduced and the empirical formula was absorbed to form a mathematical model of shock wave overpressure.Parametric numerical simulations of free-field air explosions were conducted.By experimental verification of the AUTODYN numerical method and comparing the analytical and simulated curves,the model is proved to be accurate to calculate the shock wave overpressure under free-field air explosion.In addition,through the model the shock wave overpressure at different time and distance can be displayed in three dimensions.The model makes the time needed for theoretical calculation much less than that for numerical simulation.展开更多
In this paper,we present a new approach for complex system design,which allows rapid,efficient and low-cost prototyping.This approach can simplify designing tasks and go faster from system modeling to effective hardwa...In this paper,we present a new approach for complex system design,which allows rapid,efficient and low-cost prototyping.This approach can simplify designing tasks and go faster from system modeling to effective hardware implementation.Designing multi-domain systems requires different engineering competences and several tools,our approach gives a unique design environment,based on the use of VHDL-AMS modeling language and FPGA device within the same design tool.This approach is intended to enhance hardware-in-the-loop(HIL)practices with a more realistic simulation which improve the verification process in the system design flow.This paper describes the implementation of a software/hardware platform as a practical support for our approach,the feasibility and the benefits of this approach are demonstrated through a practical case study for power converter control.The obtained results show that the developed method achieves significant speed-up compared with conventional simulation,with a minimum used resources and minimum latency.展开更多
基金partially sponsored by Foundation of PLA Rocket Force
文摘The waveform of the explosion shock wave under free-field air explosion is an extremely complex problem.It is generally considered that the waveform consists of overpressure peak,positive pressure zone and negative pressure zone.Most of current practice usually considers only the positive pressure.Many empirical relations are available to predict overpressure peak,the positive pressure action time and pressure decay law.However,there are few models that can predict the whole waveform.The whole process of explosion shock wave overpressure,which was expressed as the product of the three factor functions of peak,attenuation and oscillation,was proposed in the present work.According to the principle of explosion similarity,the scaled parameters were introduced and the empirical formula was absorbed to form a mathematical model of shock wave overpressure.Parametric numerical simulations of free-field air explosions were conducted.By experimental verification of the AUTODYN numerical method and comparing the analytical and simulated curves,the model is proved to be accurate to calculate the shock wave overpressure under free-field air explosion.In addition,through the model the shock wave overpressure at different time and distance can be displayed in three dimensions.The model makes the time needed for theoretical calculation much less than that for numerical simulation.
文摘In this paper,we present a new approach for complex system design,which allows rapid,efficient and low-cost prototyping.This approach can simplify designing tasks and go faster from system modeling to effective hardware implementation.Designing multi-domain systems requires different engineering competences and several tools,our approach gives a unique design environment,based on the use of VHDL-AMS modeling language and FPGA device within the same design tool.This approach is intended to enhance hardware-in-the-loop(HIL)practices with a more realistic simulation which improve the verification process in the system design flow.This paper describes the implementation of a software/hardware platform as a practical support for our approach,the feasibility and the benefits of this approach are demonstrated through a practical case study for power converter control.The obtained results show that the developed method achieves significant speed-up compared with conventional simulation,with a minimum used resources and minimum latency.
