Author: Zhigang Wang

Publisher:

Published: 2018

Total Pages: 24

ISBN-13:

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Measurements were made to characterize the time-varying temperature field in a medium-sized methyl alcohol (methanol; CH3OH) pool fire steadily burning in a quiescent environment. A digital camera fitted with optical filters and a zoom lens was used to record the high temperature emission intensity of 14 ℗æm diameter Type S Silicon-Carbide filaments oriented horizontally at various heights above a central cross-section of a steadily burning 0.30 m diameter methanol pool fire. The camera optics focused on the filaments with a field of view of approximately 0.3 m wide by 0.6 m high. Using the optical camera, the filament was observable only for temperatures larger than 1150 K. Experiments were conducted to collect thousands of frames of 30 Hz video. In a separate experiment, a 50 ℗æm diameter thermocouple was used to acquire 3400 independent temperature measurements at several locations in the high temperature zone of the fire. A correlation was developed between the probability density functions of the radiation-corrected thermocouple measurements and the camera grayscale pixel intensity of the filament for the same fire locations. Assuming a Gaussian temperature distribution, a fitting routine was used to determine the mean temperature and its variance from the calculated filament temperature. The mean temperatures compared favorably to previously reported measurements. False color maps of temperature were produced characterizing the entire high temperature flow field as a function of time. The time-averaged temperature field for each phase of the pulsing methanol fire was also determined. The results provide insight into the dynamic character of turbulent pool fires.

Download or read book Temperature Field Measurements Using Thin Filament Pyrometry in a Medium-scale Methanol Pool Fire written by Zhigang Wang and published by . This book was released on 2018 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements were made to characterize the time-varying temperature field in a medium-sized methyl alcohol (methanol; CH3OH) pool fire steadily burning in a quiescent environment. A digital camera fitted with optical filters and a zoom lens was used to record the high temperature emission intensity of 14 ℗æm diameter Type S Silicon-Carbide filaments oriented horizontally at various heights above a central cross-section of a steadily burning 0.30 m diameter methanol pool fire. The camera optics focused on the filaments with a field of view of approximately 0.3 m wide by 0.6 m high. Using the optical camera, the filament was observable only for temperatures larger than 1150 K. Experiments were conducted to collect thousands of frames of 30 Hz video. In a separate experiment, a 50 ℗æm diameter thermocouple was used to acquire 3400 independent temperature measurements at several locations in the high temperature zone of the fire. A correlation was developed between the probability density functions of the radiation-corrected thermocouple measurements and the camera grayscale pixel intensity of the filament for the same fire locations. Assuming a Gaussian temperature distribution, a fitting routine was used to determine the mean temperature and its variance from the calculated filament temperature. The mean temperatures compared favorably to previously reported measurements. False color maps of temperature were produced characterizing the entire high temperature flow field as a function of time. The time-averaged temperature field for each phase of the pulsing methanol fire was also determined. The results provide insight into the dynamic character of turbulent pool fires.