Combustion Theory and Modelling最新文献

{"title":"Sliding mode control for longitudinal oscillating combustion","authors":"Long Zhang, Xingyu Su, Hua Zhou, Z. Ren","doi":"10.1080/13647830.2023.2197409","DOIUrl":"https://doi.org/10.1080/13647830.2023.2197409","url":null,"abstract":"Considerable research has been reported on developing effective active control means to suppress oscillating combustion. The typical pressure oscillation can be divided into linear growth, transition and saturation stages. In this study, a sliding mode control strategy, consisting of a state estimate model, disturbance observers and a sliding mode controller, is proposed to suppress the longitudinal oscillating combustion. The control strategy is first tested with a nonlinear 0D state space model as the controlled plant. Results show that the state estimate model combined with the singular spectrum analysis (SSA) method can accurately estimate the system state quantities by grouping the SSA modes according to the frequency difference and calculating mode envelopes. To ensure the estimate accuracy, the number of truncated SSA modes varies according to the oscillation stage. The disturbance observers are designed to improve the robustness of the controller by introducing broadband spectrum disturbance to account for the external noise in the observed values. The sliding mode controller can limit the disturbance amplitude, and effectively suppress the pressure oscillation. A 1D Rijke tube acoustic network is also tested to further validate the controller adaptability. With this controller, the Rijke tube pressure oscillation can be effectively eliminated when control starts at the linear growth, transition, or saturation stages.","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"653 - 684"},"PeriodicalIF":1.3,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47937817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of artificial flame front thickening on intermediate minor species prediction using the LES–FGM method","authors":"Weijie Zhang, Quan Zhou, Jinhua Wang, Zuohua Huang","doi":"10.1080/13647830.2023.2195375","DOIUrl":"https://doi.org/10.1080/13647830.2023.2195375","url":null,"abstract":"Two stratified premixed Cambridge/Sandia flames SwB1 and SwB9 are modelled using the Flamelet-Generated Manifold in the context of Large-eddy Simulation. Two kinds of sub-grid closure models are adopted and systematically compared, that is, the Dynamically Thickened Flame (DTF) and the Presumed Probable Density Function (PPDF) models, in order to study the effects of artificial flame front thickening introduced by the DTF on the intermediate minor species prediction. It is found that the two methods lead to similar modelling of velocity, temperature, mixture fraction and major species (e.g. CH , O , CO and H O). However, the intermediate minor species CO and H can be over-predicted using the DTF model compared to the PPDF. A correction method proposed recently by Gruhlke et al. is validated in this work to improve the CO/H predictions of DTF. The corrected CO/H mass fractions are nearly consistent with the results of PPDF. It is examined that the Gruhlke-correction performs better if the wrinkling factor is used directly without modification. Meanwhile, the correction exhibits similar good performance with different level of flame front thickening and mixture stratification. The correction is also addressed to correct the species only in the flame front. The results are significant in high-fidelity simulation of intermediate species using the DTF model.","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"627 - 644"},"PeriodicalIF":1.3,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44905471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the numerical approach to the prediction of flame spread over non-planar surface of solid combustibles","authors":"A. Shaklein, A. Karpov","doi":"10.1080/13647830.2023.2197408","DOIUrl":"https://doi.org/10.1080/13647830.2023.2197408","url":null,"abstract":"The flame spread over a non-planar surface of solid fuel has been studied numerically by the coupled model of heat transfer using the proposed approach for the evaluation of burning surface regression. The boundary conditions for the surface regression rate are formulated by the combination of flame spread modes over the vertical and horizontal surfaces resulted from the staircase shape of the burning surface. Numerical results showed a good agreement with the experiment on surface regression profile and mass loss of PMMA solid fuel.","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"645 - 652"},"PeriodicalIF":1.3,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43883187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A theoretical study on the relationship between pressure rise and the Damköhler number of end-gas auto-ignition in spark-ignited engines","authors":"Shinji Hayashi, Yasuyuki Sakai, Kotaro Tanaka","doi":"10.1080/13647830.2023.2188259","DOIUrl":"https://doi.org/10.1080/13647830.2023.2188259","url":null,"abstract":"The pressure rise caused by end-gas auto-ignition in spark-ignited engines is discussed using numerical simulation and theoretical approaches. The main objective of this study is to explain the mechanism by which the end-gas expansion during auto-ignition suppresses the pressure rise in spark-ignited engines, and theoretically to demonstrate using asymptotic analysis that the pressure rise depends on the Damköhler number. A one-dimensional direct numerical simulation (DNS) of end-gas auto-ignition is performed, and the modelling assumptions for it are discussed based on the DNS results. The Damköhler number, defined as the acoustic time scale and the characteristic time scale of the chemical reaction, is introduced in the modelling. The end-gas auto-ignition model is solved numerically, and it is shown that the pressure rise increases with the Damköhler number. Additionally, it is shown that the tendency of the pressure rise is due to the balance between the propagation rate of the expansion wave generated in the end gas and the reaction rate at auto-ignition, which varies with the Damköhler number. To derive the analytical solution of the relationship between the pressure rise and Damköhler number, the end-gas auto-ignition model is simplified based on the numerical results. The simplified model for end-gas auto-ignition is then solved using Newton’s method, and the analytical solution of the pressure rise is derived.","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"605 - 626"},"PeriodicalIF":1.3,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44865124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling of acetaldehyde and acetic acid combustion","authors":"Fekadu Mosisa Wako, G. Pio, E. Salzano","doi":"10.1080/13647830.2023.2178973","DOIUrl":"https://doi.org/10.1080/13647830.2023.2178973","url":null,"abstract":"Despite the beneficial impact of biofuels on most regulated pollutants and carbon dioxide emissions, their combustion results in the generation of undesired pollutants, such as acetaldehyde and acetic acid. To better understand the chemistry of these species, detailed chemical kinetic models deriving from two alternative strategies for mechanism generation were developed and validated against available data. The first model represents a semi-lumped mechanism comprising 89 species and 366 reactions, whereas the latter is automatically generated to aggregate elemental steps based on a rate-based algorithm, and it contains 541 species and 27,334 reactions. Under the studied conditions, the two kinetic models fairly predicted ignition delay times and laminar burning velocity data of acetic acid and acetaldehyde. Few discrepancies were observed for ignition delay time at temperatures lower than 1300 K. However, the overall agreement between experimental measurements and numerical estimations allowed for the use of the two kinetic models to unravel the chemistry of the investigated species. Highlights Identification of key primary reactions for acetic acid and acetaldehyde Integration of an existing kinetic mechanism with selected reactions Development of a detailed kinetic mechanism through an automated algorithm Comparison of experimental and numerical data for overall reactivity Analysis of the chemistry of acetic acid and acetaldehyde","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"536 - 557"},"PeriodicalIF":1.3,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42987792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient two-dimension particle element method of interior ballistic two-phase flow","authors":"Chen Shenshen, Tao Ruyi, Lu Xinggan, Xue Shao, Jiang Kun","doi":"10.1080/13647830.2023.2178974","DOIUrl":"https://doi.org/10.1080/13647830.2023.2178974","url":null,"abstract":"Reducing the calculation cost is of great importance as the demand for interior ballistic calculation is increasing. The key factor of interior ballistic simulation is the quest to develop a more efficient method. In this paper, an efficient two-dimension particle element method (PEM) is proposed to simulate the detailed multidimensional flow of the gas and propellant particle in the chamber. Firstly, several real particles are packed as the particle element to reduce the calculation of the solid phase. In particular, the particle element matrix is established to describe the distribution of particle parameters. Secondly, the particle element boundary is adjusted according to the particle’s movement to reduce the computational cost of grid generation. Besides, the dynamic self-adapting mesh map method is adopted to realise the coupling computation between gas phase and the particle element. The application of a standard virtual gun as a standard benchmark for interior ballistic codes is used to validate the accuracy and reliability with 1.68% error. The particle element model accurately describes the distribution of flow field in the chamber. Compared with the two-fluid method, the PEM significantly improves the computational efficiency by 21.7%. The PEM may be promising for the rapid simulation of two-phase flow in interior ballistic.","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"558 - 583"},"PeriodicalIF":1.3,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41750572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A thick reaction zone model for premixed flames in two-dimensional channels","authors":"P. Rajamanickam, J. Daou","doi":"10.1080/13647830.2023.2174046","DOIUrl":"https://doi.org/10.1080/13647830.2023.2174046","url":null,"abstract":"Direct interactions between the flow field and the chemical reaction in premixed flames occur when the reaction zone thickness is comparable to, or greater than flow length scales. To study such interactions, a laminar model is considered that has direct bearings to steadily propagating deflagrations in a Hele-Shaw channel with a background plane Poiseuille flow. The study employs asymptotic analyses, pertaining to large activation energy and lubrication theories and considers a distinguished limit where the channel width is comparable to the reaction zone thickness, with account being taken of thermal-expansion and heat-loss effects. The reaction zone structure and burning rates depend on three parameters, namely, the Peclet number, , the Lewis number, and the ratio of channel half-width to reaction zone thickness, . In particular, when the parameter is small wherein the reaction zone is thick, transport processes are found to be controlled by Taylor's dispersion mechanism and an explicit formula for the effective burning speed is obtained. The formula indicates that for , which interestingly coincides with a recent experimental prediction of the turbulent flame speed in a highly turbulent jet flame. The results suggest that the role played by differential diffusion effects is significant both in the laminar and turbulent cases. The reason for the peculiar dependence can be attributed, at least in our laminar model, to Taylor dispersion. Presumably, this dependence may be attributed to a similar but more general mechanism in the turbulent distributed reaction zone regime, rather than to diffusive-thermal curvature effects. The latter effects play however an important role in determining the effective propagation speed for thinner reaction zones, in particular, when is large in our model. It is found that the magnitude of heat losses at extinction, which directly affects the mixture flammability limits, is multiplied by a factor in comparison with those corresponding to the no-flow case in narrow channels.","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"487 - 507"},"PeriodicalIF":1.3,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46994718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of an innovative sampling strategy based on k-means clustering algorithm for POD and POD-DEIM reduced order models of a 2-D reaction-diffusion system","authors":"E. A. Cutillo, Gianmarco Petito, K. Bizon, G. Continillo","doi":"10.1080/13647830.2023.2174451","DOIUrl":"https://doi.org/10.1080/13647830.2023.2174451","url":null,"abstract":"In this work, a model-order reduction methodology based on proper orthogonal decomposition (POD) and Galërkin projection is presented and applied to the simulation of the self-ignition of a stockpile of solid fuel. Self-ignition is a phenomenon associated with steep changes in space and time, yielding high gradients of state variables which demand grid refinement and, thus, increase of the computational burden. To cope with this difficulty, first, a full order model (FOM), generated by finite-difference discretisation of the PDEs constituting the differential model, is employed to generate reference solutions. Two different POD-based formulations are proposed: the classical POD-Galërkin is employed to generate reduced order models (ROM), then discrete empirical interpolation method (DEIM) is employed to deal with nonlinearities in a more efficient manner. These reduction techniques are further supplemented with an innovative sampling approach based on k-means clustering. The resulting agile ROM is validated against the FOM. Both model-order reduction strategies, particularly the POD-DEIM model, reproduce the FOM solutions with high accuracy and much lower computational cost: The results of the application of a combination of the DEIM algorithm and k-means clustering show that the computational time for the calculation of one solution reduces up to 1020 times, while remaining able to reproduce all bifurcation points found with the FOM, thus demonstrating quantitative and qualitative agreement.","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"508 - 535"},"PeriodicalIF":1.3,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46915190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simulation and performance improvement of an industrial steam methane reformer: depreciation and ceramic coating effects","authors":"Saeedeh Hamoudi, A. Mirvakili, A. Jamekhorshid, Mohamad Gholipour","doi":"10.1080/13647830.2023.2169636","DOIUrl":"https://doi.org/10.1080/13647830.2023.2169636","url":null,"abstract":"In this work, Computational Fluid Dynamic (CFD) is applied to compare the performance of an industrial reformer furnace in four cases. The first and tenth years of operation are two cases with different emissivity factors and fuel components. The results are validated with industrial data and with other CFD simulation typical plants reported in the SMR literature. The results show that a 10% increase in fuel consumption in the tenth year cannot compensate for all temperature drop in skin tubes, and there is still a 14 K temperature drop, leading to a 5% decrease in hydrogen production in tubes. This is due to the different fuel components of the tenth year compared to the first year. To examine the effect of fuel change more closely, the third case is defined with the fuel components of the tenth year and the emissivity factor of the first year. The comparison of this case with others shows that fuel components have a high effect on system performance. The major reason for efficiency reduction between the first and tenth years correlates to a 50% decline in the wall surface emissivity factor. Finally, in the fourth case, applying a ceramic coating with a high emissivity factor is considered via the CFD model for the reformer in the tenth year. This change leads to an increase of about 19 K in tube temperature in the tenth year, which is 3 K more than that in the first year. It can be concluded that the ceramic coating application in the wall of the refractory of the reformer can reduce 14% fuel consumption and enhance hydrogen production.","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"418 - 440"},"PeriodicalIF":1.3,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45428193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive influence of uncertainty propagation of chemical kinetic parameters on laminar flame speed prediction: a case study of dimethyl ether","authors":"Yachao Chang, Pengzhi Wang, Shuai Huang, Xu Han, Ming-lei Jia","doi":"10.1080/13647830.2023.2169637","DOIUrl":"https://doi.org/10.1080/13647830.2023.2169637","url":null,"abstract":"The uncertainties existing in the parameters of chemical kinetic models have a non-negligible influence on the model predictions. It is necessary to conduct a quantitative uncertainty analysis to explore the influence of each parameter on chemical mechanism predictions. To comprehensively consider the effect of the uncertainties of reaction rate parameters, thermodynamic parameters, and transport parameters on model predictions, local sensitivity analysis, local-sensitivity-based uncertainty analysis (LSUA), and random-sampling high dimensional model representation (RS-HDMR) method were coupled to investigate the uncertainty propagation of the chemical kinetic parameters to the calculated laminar flame speed of dimethyl ether under a wide range of conditions using a detailed mechanism. First, the uncertainty analysis was conducted using the local sensitivity analysis and the LSUA method under a wide range of operating conditions to identify the important operating conditions and chemical kinetic parameters. It is found that the prediction uncertainty of laminar flame speed is more obvious under the conditions of high dilution ratio, high pressure, and large equivalence ratio than that under other conditions. According to the results of LSUA, the prediction uncertainty is mainly from the reaction rate coefficients and thermodynamic data. Then, the uncertainty propagation from the significant parameters to the calculated laminar flame speed under important conditions was analysed using the RS-HDMR method. To reduce the huge computational cost of the RS-HDMR method, the backpropagation artificial neural network was employed. The RS-HDMR results indicate that the reaction H + O2 = O + OH has the highest sensitivity coefficient under the whole investigated conditions, which is different from the results using the LSUA method. The non-linear relationship between the rate coefficient and the predicted laminar flame speed is responsible for the discrepancy. Furthermore, it is found that the sensitivity coefficient of the input parameters strongly depends on the operating conditions.","PeriodicalId":50665,"journal":{"name":"Combustion Theory and Modelling","volume":"27 1","pages":"441 - 458"},"PeriodicalIF":1.3,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43665867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}