Anna Kucaba-Pietal

Experimental testing of journal bearings with two-component surface layer in the presence of an oil abrasive contaminant

The aim of the paper is to present a new design of the two-component surface layer journal and the experimental results indicating usefulness of the new design. The novelty of the design consists of placing soft material stripes on the bearing journal surface and forming microgrooves in the material contact zone. Experiments indicate clearly on the usefulness of the design, especially in the case when oil is contaminated by hard particles. In every stage of testing, the sensitivity to contamination of the bearing with the two-component surface layer journal is about one-fifth that of the case of the conventional bearing.

Data acquisition system for PW-6U in flight boundary layer mapping

Purpose This paper aims to describe an idea for an integration process and tests of flight parameters measurement system, which supports infrared thermography (IRT) boundary layer mapping. Design/methodology/approach The study of flow changes in the boundary layer with the use of IRT requires registration of the thermal images of the selected area of a wing or the fuselage, as well as synchronous recording of flight parameters. These tasks were realized by the supplementary measurement system mounted on the PW-6U glider. Two examples of the determination of the laminar-turbulent transition areas on the left wing of a PW-6U glider are also presented in the paper. Findings Optical methods can be used in several research areas, for example, aerodynamics and strength analysis. For instance, the measurement of the infrared radiation from surfaces with the use of IRT can be used for the measurement, with high accuracy, of surface temperature distribution. Moreover, the thermography is used for the analysis of the boundary layer. Performed in-flight experiments confirm the possibility of practical usage of the IRT method even on the board of a glider. Practical implications The use of optical methods will, in many cases, be less expensive than assembly of an additional measurement and data acquisition systems. Implementation of optical methods for industrial purposes has many advantages, and, hence, they will probably become very common in the future. Originality/value The study introduces advanced measurement and visualization techniques in general aviation.

Studying the Performance Nonlinear Systems Solvers Applied to the Random Vibration Test

In this paper we compare the performance of four solvers for systems of nonlinear algebraic equations applied to the random vibration test, which requires a solution of a system of 512 or more equations. Experimental results obtained for two test cases are presented and discussed.

Application of Boundary Collocation Method in Fluid Mechanics to Stokes Flow Problems

The aim of this work is to present a short review of application of the boundary collocation technique to some problems in fluid mechanics. The steps used to find interaction between a wall and a sphere moving axisymetrically towards the flat wall in micropolar fluid are outlining to illustrate workability of the method. This problem occurs in modeling flow problems in microdevices as well as in human joins.

Solvers for Systems of Nonlinear Algebraic Equations - Their Sensitivity to Starting Vectors

In this note we compare the sensitivity of six advanced solvers for systems of nonlinear algebraic equations to the choice of starting vectors. We will report on results of our experiments in which, for each test problem, the calculated solution was used as the center from which we have moved away in various directions and observed the behavior of each solver attempting to find the solution. We are particularly interested in determining the best global starting vectors. Experimental results are presented and discussed.

Can we use virtual reality tools in the planning of an experiment

Virtual reality (VR) has proved to be a particularly useful tool in engineering and design. A related area of aviation in which VR is particularly significant is a flight training, as it requires many hours of practice and using real planes for all training is both expensive and more dangerous. Research conducted at the Rzeszow University of Technology (RUT) showed that virtual reality can be successfully used for planning experiment during a flight tests. Motivation to the study were a wing deformation measurements of PW-6 glider in flight by use Image Pattern Correlation Technique (IPCT) planned within the frame of AIM 2 project. The tool VirlIPCT was constructed, which permits to perform virtual IPCT setup on an airplane. Using it, we can test a camera position, camera resolution, pattern application. Moreover performed tests on RUT indicate, that VirlIPCT can be used as a virtual IPCT image generator. This paper presents results of the research on VirlIPCT.