2018 Flow Control Conference最新文献_第7页

Open- and closed-loop control investigations of unsteady Coanda actuation on a high-lift configuration 大升力结构非定常Coanda驱动的开闭环控制研究

2018 Flow Control Conference Pub Date : 2018-06-24 DOI: 10.2514/6.2018-3684

M. Sayed, P. Oswald, S. Sattler, Pradeep Kumar, R. Radespiel, C. Behr, M. Sinapius, Jan Petersen, P. Wierach, M. Quade, Markus Abel, B. R. Noack, R. Semaan

引用次数: 7

Wavy Leading Edge Phenomena on Transonic Flow Regime 跨声速流型的波浪前缘现象

2018 Flow Control Conference Pub Date : 2018-06-24 DOI: 10.2514/6.2018-4254

Vinicius A. Sepetauskas, Bruno Massucatto, A. A. D. Paula, R. G. D. Silva

引用次数: 3

Transonic Super-critical Airfoil Enhancement by Coflow Jet Downstream of Normal Shock 法向激波下游共流射流增强跨音速超临界翼型

2018 Flow Control Conference Pub Date : 2018-06-24 DOI: 10.2514/6.2018-3376

Michael G. Fernandez, J. N. Hoffmann, Gecheng Zha

{"title":"Transonic Super-critical Airfoil Enhancement by Coflow Jet Downstream of Normal Shock","authors":"Michael G. Fernandez, J. N. Hoffmann, Gecheng Zha","doi":"10.2514/6.2018-3376","DOIUrl":"https://doi.org/10.2514/6.2018-3376","url":null,"abstract":"This paper performs a numerical study to enhance transonic supercritical Coflow Jet (CFJ) airfoil cruise performance by placing the CFJ downstream of the normal shock wave. The Reynolds averaged Navier-Stokes(RANS) equations with one-equation SpalartAllmaras turbulence model is used. A 3rd order weighted essentially non-oscillatory (WENO) scheme with a low diffusion Riemann solver is utilized to evaluate the inviscid fluxes. A 2nd order central differencing scheme is employed for the viscous terms. Numerical trade studies are carried out to investigate CFJ location effects on the shock location and the airfoil efficiency enhancement. This research discovers that placing a CFJ downstream of a shock wave, results in an induction effect that moves the shock further downstream with enlarged supersonic region. Furthermore, the CFJ placed downstream of the shock wave will not suffer the entropy increase due to the shock boundary interaction occurring between the CFJ injection and suction. It substantially reduces the CFJ power expenditure. The effects enhance the cruise efficiency of the supercritical airfoil for both the coefficient of lift CL and the aerodynamic efficiency ( L D )c, which takes into consideration the power required to run the CFJ. The study shows that the aerodynamic efficiency is increased by 5.26% over the baseline RAE2822 and decreasd by 6.68% over the standard CFJ-RAE2822. Measuring by peak (C L/CD)c results in an efficiency increase of 6.68% over the baseline RAE2822 and a decrease of 17.51% over standard CFJ-RAE2822.","PeriodicalId":144668,"journal":{"name":"2018 Flow Control Conference","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124149145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Revisiting the separation principle for improved transition control 为改进过渡控制重温分离原理

2018 Flow Control Conference Pub Date : 2018-06-24 DOI: 10.2514/6.2018-3693

Huaijin Yao, Maziar S. Hemati

{"title":"Revisiting the separation principle for improved transition control","authors":"Huaijin Yao, Maziar S. Hemati","doi":"10.2514/6.2018-3693","DOIUrl":"https://doi.org/10.2514/6.2018-3693","url":null,"abstract":"Feedback control can be used to suppress transient energy growth and delay turbulent transition in shear flows. The separation principle of modern control theory is commonly invoked to design observer-based control laws, whereby a full-state feedback controller and a state estimator are designed independently, then combined to achieve an output feedback flow control law. In previous work, we established that transient energy growth can never be fully eliminated by observer-based control, even when an associated full-state feedback law can fully suppress such growth. In this paper, we use a linearized channel flow to show that observer-based feedback will lead to higher levels of transient energy growth than if no control is used at all. Further, we show that transient energy growth can actually be reduced via optimal static output feedback controllers, thus overcoming the performance limitations of observer-based designs. We introduce a modified AndersonMoore algorithm for efficiently computing optimal static output feedback controllers, then show that the resulting controllers reduce the worst-case transient energy growth relative to the uncontrolled system and to observer-based designs. Further, our results indicate that optimal static output feedback exhibits robustness to Reynolds number variations and modeling uncertainty. The result of this study highlight the advantages of optimal static output feedback control over observer-based designs and create opportunities for realizing improved transition control strategies in the future.","PeriodicalId":144668,"journal":{"name":"2018 Flow Control Conference","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124585557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Closed-loop active flow control of repetitive disturbances in a linear stator cascade 线性定子级联中重复扰动的闭环主动流量控制

2018 Flow Control Conference Pub Date : 2018-06-24 DOI: 10.2514/6.2018-3689

S. Steinberg, R. King

引用次数: 1

Near-Wake Flow Modulation by A Cube On A Backward-Facing Ramp 后向斜坡上立方体的近尾流调制

2018 Flow Control Conference Pub Date : 2018-06-24 DOI: 10.2514/6.2018-3526

S. Tandon, Siddhesh Shinde, K. Maki, E. Johnsen

引用次数: 2

Preliminary Experimental Study on Closed-loop Flow Separation Control Utilizing Deep Q-Network over Fixed Angle-of-Attack Airfoil 基于深q网络的固定迎角翼型闭环流分离控制初步实验研究

2018 Flow Control Conference Pub Date : 2018-06-24 DOI: 10.2514/6.2018-3522

Satoshi Shimomura, S. Sekimoto, Hiroaki Fukumoto, A. Oyama, K. Fujii, H. Nishida