Application of B Splines to Identification of the Movement Equations of the Floating Objects

The paper presents the possibilities of using B-splines to determine a mathematical model in the form of linear differential equations describing the change of the motion parameters of floating objects depending on the values of the control signals. The elaborated identification system is a collection of algorithms including: approximation of input and output signals, optimal selection of differential equation coefficients and model verification. The basic spline functions were used to approximate the values of the input and output signals. The developed method was illustrated by an example of identification of underwater submarine motion equations describing the change in draft depth and trim angle depending on the difference between buoyancy force and ship’s weight

Diagnostic Model of Fuel Installation of Marine Diesel Engine

The paper presents the results of simulation of marine diesel engine fuel injector malfunction and its effects on engine vibration. The work includes the analysis of the engine internal forces and their mathematical models. Simplifications are proposed to allow analyzing the system in one degree of freedom. The results of vibration simulations for the model with efficient fuel system and improperly adjusted injector are also presented. The comparison of simulation results with vibration measurements on the engine was also performed, the diagnostic model was identified and simulation errors were calculated. The complexity of other internal and external interactions is the subject of other studies by the authors. The paper analyzes only the effects of energy dissipation - vibration as a symptom of changes in the technical condition

The Single Degree of Freedom Simulation Model of Underwater Explosion Impact

The hulls of naval ships are exposed to forces and moments coming from internal and external sources. Usually, these are interactions that can be described mathematically by harmonic and polyharmonic functions. The shock of UNDEX type (underwater explosion) works completely differently and its time waveform is difficult to describe with mathematical functions as pressure vs. time. The paper presents a simplification of physical and mathematical models of 1-D kickoff pressure whose aim is performance the simulation of the external force of the detonation wave. The proposed models were verified and tuned on naval, sea trials. The main goals of the proposed models are to perform simulation calculations of the detonation pressure for different explosion charge weights from different distances of the UNDEX epicentre for the design process of machine foundation. The effects of pressure are transformed as impulses exposed on shock absorber mounted at light shock machine