Evaluation techniques for optical analysis of hybrid rocket propulsion
This article summarizes recent results of data evaluation techniques obtained with optical investigations on the combustion behavior of hybrid rocket fuels. Tests are performed in a 2D slab burner configuration with windows on two sides. Liquefying paraffin-based fuels are tested in combination with...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
The Japan Society of Mechanical Engineers
2016-12-01
|
| Series: | Journal of Fluid Science and Technology |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/jfst/11/4/11_2016jfst0028/_pdf/-char/en |
| _version_ | 1798020931948380160 |
|---|---|
| author | Anna PETRAROLO Mario KOBALD |
| author_facet | Anna PETRAROLO Mario KOBALD |
| author_sort | Anna PETRAROLO |
| collection | DOAJ |
| description | This article summarizes recent results of data evaluation techniques obtained with optical investigations on the combustion behavior of hybrid rocket fuels. Tests are performed in a 2D slab burner configuration with windows on two sides. Liquefying paraffin-based fuels are tested in combination with gaseous oxygen (GOX). High speed videos of combustion tests are recorded in order to investigate the combustion phenomena of this kind of fuels. Hybrid combustion of liquefying fuels is dominated by transient flow dynamics like Kelvin-Helmholtz instability and vortex shedding, also due to the characteristic turbulent diffusion flame. In order to better evaluate these flow phenomena, characteristic frequencies and wavelengths of the main structures of the flow field and of the combustion flame appearing in the video data have to be found. In this work, a spatial and temporal analysis of these structures is carried out by using two different techniques, applied within an automated video evaluation routine. First of all, the Proper Orthogonal Decomposition (POD) technique is used. Its results deliver linearly uncorrelated variables, which are the principal components of the flow field. This method enables to recognize the main structures of the flow field and the combustion flame appearing in the video data. Secondly, the Independent Component Analysis (ICA) technique is applied to the same data. It is able to search for statistically independent, or as independent as possible, structures hidden in the data. It increases the independence to higher statistical orders with respect to POD. The basis functions found with the ICA are expected to describe the essential structure of the data and to resemble some physical processes involved in the combustion. With both methods it is possible to compute spatial and temporal coefficients, which can be later analyzed by applying a Power Spectral Density (PSD) in order to obtain the excited frequencies and wavelengths during the combustion. Finally, the results of the two methods are compared in order to better understand and interpret them. The results collected so far and the comparison of both techniques show that their application is consistent and useful for the automated evaluation of combustion data. |
| first_indexed | 2024-04-11T17:05:43Z |
| format | Article |
| id | doaj.art-5bd534b454614b51b4ade2e692fbef5c |
| institution | Directory Open Access Journal |
| issn | 1880-5558 |
| language | English |
| last_indexed | 2024-04-11T17:05:43Z |
| publishDate | 2016-12-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Fluid Science and Technology |
| spelling | doaj.art-5bd534b454614b51b4ade2e692fbef5c2022-12-22T04:13:01ZengThe Japan Society of Mechanical EngineersJournal of Fluid Science and Technology1880-55582016-12-01114JFST0028JFST002810.1299/jfst.2016jfst0028jfstEvaluation techniques for optical analysis of hybrid rocket propulsionAnna PETRAROLO0Mario KOBALD1German Aerospace Center (DLR)German Aerospace Center (DLR)This article summarizes recent results of data evaluation techniques obtained with optical investigations on the combustion behavior of hybrid rocket fuels. Tests are performed in a 2D slab burner configuration with windows on two sides. Liquefying paraffin-based fuels are tested in combination with gaseous oxygen (GOX). High speed videos of combustion tests are recorded in order to investigate the combustion phenomena of this kind of fuels. Hybrid combustion of liquefying fuels is dominated by transient flow dynamics like Kelvin-Helmholtz instability and vortex shedding, also due to the characteristic turbulent diffusion flame. In order to better evaluate these flow phenomena, characteristic frequencies and wavelengths of the main structures of the flow field and of the combustion flame appearing in the video data have to be found. In this work, a spatial and temporal analysis of these structures is carried out by using two different techniques, applied within an automated video evaluation routine. First of all, the Proper Orthogonal Decomposition (POD) technique is used. Its results deliver linearly uncorrelated variables, which are the principal components of the flow field. This method enables to recognize the main structures of the flow field and the combustion flame appearing in the video data. Secondly, the Independent Component Analysis (ICA) technique is applied to the same data. It is able to search for statistically independent, or as independent as possible, structures hidden in the data. It increases the independence to higher statistical orders with respect to POD. The basis functions found with the ICA are expected to describe the essential structure of the data and to resemble some physical processes involved in the combustion. With both methods it is possible to compute spatial and temporal coefficients, which can be later analyzed by applying a Power Spectral Density (PSD) in order to obtain the excited frequencies and wavelengths during the combustion. Finally, the results of the two methods are compared in order to better understand and interpret them. The results collected so far and the comparison of both techniques show that their application is consistent and useful for the automated evaluation of combustion data.https://www.jstage.jst.go.jp/article/jfst/11/4/11_2016jfst0028/_pdf/-char/enhybrid rocket propulsionparaffin fueloptical investigationproper orthogonal decompositionindependent component analysis |
| spellingShingle | Anna PETRAROLO Mario KOBALD Evaluation techniques for optical analysis of hybrid rocket propulsion Journal of Fluid Science and Technology hybrid rocket propulsion paraffin fuel optical investigation proper orthogonal decomposition independent component analysis |
| title | Evaluation techniques for optical analysis of hybrid rocket propulsion |
| title_full | Evaluation techniques for optical analysis of hybrid rocket propulsion |
| title_fullStr | Evaluation techniques for optical analysis of hybrid rocket propulsion |
| title_full_unstemmed | Evaluation techniques for optical analysis of hybrid rocket propulsion |
| title_short | Evaluation techniques for optical analysis of hybrid rocket propulsion |
| title_sort | evaluation techniques for optical analysis of hybrid rocket propulsion |
| topic | hybrid rocket propulsion paraffin fuel optical investigation proper orthogonal decomposition independent component analysis |
| url | https://www.jstage.jst.go.jp/article/jfst/11/4/11_2016jfst0028/_pdf/-char/en |
| work_keys_str_mv | AT annapetrarolo evaluationtechniquesforopticalanalysisofhybridrocketpropulsion AT mariokobald evaluationtechniquesforopticalanalysisofhybridrocketpropulsion |