Effects of depth and forward speed on hydrodynamic coefficients of ships are presented in this paper. A modified simple Green function technique was used to calculate 2D coefficients while strip theory was used to cal...Effects of depth and forward speed on hydrodynamic coefficients of ships are presented in this paper. A modified simple Green function technique was used to calculate 2D coefficients while strip theory was used to calculate 3D coefficients. Numerical results are provided for hydrodynamic coefficients of parabolic hull ship. It is found out that both depth and forward speed have considerable effects on hydrodynamic coefficients of ship.展开更多
Choosing the equipment with good shock-resistant p erformance and taking shock protection measures while designing the onboard sett ings, the safety of onboard settings can be assured when warships, especially su bmar...Choosing the equipment with good shock-resistant p erformance and taking shock protection measures while designing the onboard sett ings, the safety of onboard settings can be assured when warships, especially su bmarine subjected to non-contact underwater explosion, that is, these means can be used to limit the rattlespace (i.e., the maximum displacement of the equipme nt relative to the base) and the peak acceleration experienced by the equipment. Using shock-resistant equipments is one of shock protection means. The shock- resistant performance of the shock-resistant equipments should be verified in t he design phase of the equipments. The FEA (finite element analysis) software, for example, MSC.NASTRAN ○R , can be used to verify the shock-resistant performance. MSC.PATRAN ○R and MSC.NASTRAN are used for modeling and analyzing the floating raft vibration isolating equipment. The model of the floating raft and the floating raft vibration isolating system are theoretically analyzed and calculated, and the analysis results are in agreement with the test results. The transient response analysis of the system model follows the modal analysis of the floating raft vibration isolating system. And it is used to verify the shock-resistant performance. The ana lysis and calculation method used in this paper can be used to analyze the shock -resistant performance of onboard shock-resistant equipments.展开更多
Exactly modeling of anti-shock isolation system of a marinein its design.For an isolation system with some rigid stops,the enginebody and isolators as springs and dampers,for which three nonlinearengine is an importan...Exactly modeling of anti-shock isolation system of a marinein its design.For an isolation system with some rigid stops,the enginebody and isolators as springs and dampers,for which three nonlinearengine is an important stepcan be modeled as a rigidfactors exist.This paper isaimed at that whether there are any nonlinear factors can be neglected?In this paper, the marine en-gine with anti-shock isolation system is firstly suggested as a vibro-impact system to study.An ap-proximate discrete model described by impact Poincaré map can be derived.Analysis of example shows that O-order approximate model conceals possible chaotic phenomenon; simultaneously,limiting clearance of stops can influence bifurcation area in bifurcation diagram.展开更多
文摘Effects of depth and forward speed on hydrodynamic coefficients of ships are presented in this paper. A modified simple Green function technique was used to calculate 2D coefficients while strip theory was used to calculate 3D coefficients. Numerical results are provided for hydrodynamic coefficients of parabolic hull ship. It is found out that both depth and forward speed have considerable effects on hydrodynamic coefficients of ship.
文摘Choosing the equipment with good shock-resistant p erformance and taking shock protection measures while designing the onboard sett ings, the safety of onboard settings can be assured when warships, especially su bmarine subjected to non-contact underwater explosion, that is, these means can be used to limit the rattlespace (i.e., the maximum displacement of the equipme nt relative to the base) and the peak acceleration experienced by the equipment. Using shock-resistant equipments is one of shock protection means. The shock- resistant performance of the shock-resistant equipments should be verified in t he design phase of the equipments. The FEA (finite element analysis) software, for example, MSC.NASTRAN ○R , can be used to verify the shock-resistant performance. MSC.PATRAN ○R and MSC.NASTRAN are used for modeling and analyzing the floating raft vibration isolating equipment. The model of the floating raft and the floating raft vibration isolating system are theoretically analyzed and calculated, and the analysis results are in agreement with the test results. The transient response analysis of the system model follows the modal analysis of the floating raft vibration isolating system. And it is used to verify the shock-resistant performance. The ana lysis and calculation method used in this paper can be used to analyze the shock -resistant performance of onboard shock-resistant equipments.
文摘Exactly modeling of anti-shock isolation system of a marinein its design.For an isolation system with some rigid stops,the enginebody and isolators as springs and dampers,for which three nonlinearengine is an important stepcan be modeled as a rigidfactors exist.This paper isaimed at that whether there are any nonlinear factors can be neglected?In this paper, the marine en-gine with anti-shock isolation system is firstly suggested as a vibro-impact system to study.An ap-proximate discrete model described by impact Poincaré map can be derived.Analysis of example shows that O-order approximate model conceals possible chaotic phenomenon; simultaneously,limiting clearance of stops can influence bifurcation area in bifurcation diagram.
