Investigation of the Accuracy of the Temperature Field Calculations with Forward Projected Background Oriented Schlieren
S. Kottakalam(1), G. Morello(2), G. Rottenkolber(1)
1: Faculty of Mobility and Technology, Esslingen University of Applied Sciences, Germany
2: Faculty Engineering, Hochschule Heilbronn - University of Applied Sciences, Germany
DOI:
This study involves the investigation of the accuracy of a Forward Projected Background Oriented Schlieren (FPBOS) setup for understanding spark ignition phenomenon in internal combustion engines. The experiment is setup with the goal of measuring the temperature of the volume heated by the spark in a J-gap spark plug. This work utilizes a calibration technique which uses a known density gradient (Helium jet) of varying thickness to calibrate the experimental setup used for measuring sparks. Helium jets of diameter ranging from 1.0 mm to 2.5 mm was used for the calibration since this is the expected thickness range of the heated volume to be measured. Further investigations were also performed for understanding the sensitivity of the measurement technique on the thickness of the density gradient used for calibration. In addition to this, investigations to understand the influence of the distance between the density gradient and the background pattern was also performed. This provided insight into how the movement of the spark along the electrode gap influences the accuracy of the measurement setup. This work reports crucial information on the accuracy of measurements obtained from a particular experimental setup and presents a methodology for estimating the accuracy of an FPBOS measurement setup.
