Andrzej J. Panas

Inverse problem solution for a laser flash studies of a thin layer coatings

Purpose The paper aims to discuss the inverse heat conduction methodology in solution of a certain parameter identification problem. The problem itself concerns determination of the thermophysical properties of a thin layer coating by applying the laser flash apparatus. Design/methodology/approach The modelled laser flash diffusivity data from the three-layer sample investigation are used as input for the following parameter estimation procedure. Assuming known middle layer, i.e. substrate properties, the thermal diffusivity (TD) of the side layers’ material is determined. The estimation technique utilises the finite element method for numerical solution of the direct, 2D axisymmetric heat conduction problem. Findings The paper presents methodology developed for a three-layer sample studies and results of the estimation technique testing and evaluation based on simulated data. The multi-parametrical identification procedure results in identification of the out of plane thin layer material diffusivity from the inverse problem solution. Research limitations/implications The presentation itself is limited to numerical simulation data, but it should be underlined that the flake graphite thermophysical parameters have been utilised in numerical tests. Practical implications The developed methodology is planned to be applied in detailed experimental studies of flake graphite. Originality/value In the course of a present study, a methodology of the thin-coating layer TD determination was developed. In spite of the fact that it has been developed for the graphite coating investigation, it was planned to be universal in application to any thin–thick composite structure study.

Evaluation of numerical modelling application for the crash test planning of the catastrophic Flight Data Recorder

ABSTRACT Catastrophic Flight Data Recorders (FDRs), the so-called black boxes, belong to the on-board equipment, the task of which is not only to operate properly while recording selected parameters under all flight conditions but also to protect the recorded data against the loss in the aircraft crash conditions. The requirements related to catastrophic resistance of FDRs are defined in the European standard EuroCAE ED-112 and the Polish standard NO-16-A200:2015. One of the requirements includes the catastrophic recorder’s resistance to the acceleration overload of 3400 g. The compliance with the standard is checked during crash tests. In this paper, a procedure of planning and carrying out the mentioned tests for S2-3a-K protected unit of S2-3a catastrophic FDR manufactured by the Air Force Institute of Technology was described. It is an iterative procedure involving consecutive experimental tests and both analytical and numerical calculations. The experimental tests were performed using a DPZ-250 pneumatic gun. The testing probe was shot at the target of sand deposits of modified geometry and mass characteristics. Effectiveness of the developed procedure was shown by comparing the experimental results, namely recordings of the probe deceleration captured with a fast camera, with results of numerical simulation of the probe terminal ballistic.

Testing the Catastrophic Recorder Resistance Against the Impact of Catastrophic Factors

Abstract The subject of the research was a catastrophic recorder of the S2-3a system for recording flight parameters, developed at the Air Force Institute of Technology. The article discusses tests of catastrophic recorders’ resilience to factors present at aircraft accidents. The document specifying the requirements for catastrophic recorders of flight parameters includes the defence standard: NO-16-A200, and the European standard: EuroCAE ED-112. According to NO-16-A200 and ED-112 standards, the protective unit should be resistant to: g-forces existing during crash, puncture, compression, fire, underwater pressure and aggressive liquids.