id,collection,dc.contributor.author,dc.date.accessioned,dc.date.available,dc.date.issued,dc.description.abstract[en],dc.format.extent,dc.identifier.uri,dc.language,dc.rights.uri,dc.subject,dc.subject.ddc,dc.title,dc.type,dcterms.accessRights.openaire,dcterms.bibliographicCitation,dcterms.bibliographicCitation.doi,dcterms.bibliographicCitation.url,dcterms.isPartOf.issn,refubium.affiliation.other,refubium.affiliation[de],refubium.mycore.derivateId,refubium.mycore.fudocsId,refubium.note.author,refubium.resourceType.isindependentpub "7a839407-747d-47aa-a6f8-96c45c2c8a70","fub188/16","Schäpel, Jan-Simon||Reichel, Thoralf G.||Klein, Rupert||Paschereit, Christian Oliver||King, Rudibert","2018-06-08T11:10:54Z","2018-04-05T13:08:48.147Z","2016","Changing the combustion process of a gas turbine from a constant-pressure to a pressure-increasing approximate constant-volume combustion (aCVC) is one of the most promising ways to increase the efficiency of turbines in the future. In this paper, a newly proposed method to achieve such an aCVC is considered. The so-called shockless explosion combustion (SEC) uses auto-ignition and a fuel stratification to achieve a spatially homogeneous ignition. The homogeneity of the ignition can be adjusted by the mixing of fuel and air. A proper filling profile, however, also depends on changing parameters, such as temperature, that cannot be measured in detail due to the harsh conditions inside the combustion tube. Therefore, a closed-loop control is required to obtain an adequate injection profile and to reject such unknown disturbances. For this, an optimization problem is set up and a novel formulation of a discrete extremum seeking controller is presented. By approximating the cost function with a parabola, the first derivative and a Hessian matrix are estimated, allowing the controller to use Newton steps to converge to the optimal control trajectory. The controller is applied to an atmospheric test rig, where the auto-ignition process can be investigated for single ignitions. In the set-up, dimethyl ether is injected into a preheated air stream using a controlled proportional valve. Optical measurements are used to evaluate the auto-ignition process and to show that using the extremum seeking control approach, the homogeneity of the ignition process can be increased significantly.","13 Seiten","https://refubium.fu-berlin.de/handle/fub188/21765||http://dx.doi.org/10.17169/refubium-25053","eng","http://creativecommons.org/licenses/by/4.0/","shockless explosion combustion||constant volume combustion||extremum seeking control","600 Technik, Medizin, angewandte Wissenschaften::620 Ingenieurwissenschaften::621 Angewandte Physik||500 Naturwissenschaften und Mathematik::510 Mathematik","Online Optimization Applied to a Shockless Explosion Combustor","Wissenschaftlicher Artikel","open access","Processes 4 (2016), 4","10.3390/pr4040048","http://doi.org/10.3390/pr4040048","2227-9717","Institut für Mathematik:::bbcc0fd4-8a69-48ba-bf5a-6eae54fc4a88:::600","Mathematik und Informatik","FUDOCS_derivate_000000009600","FUDOCS_document_000000029502","Der Artikel wurde in einer Open-Access-Zeitschrift publiziert.","no"