Author: Publisher:
ISBN:
Category : Rocketry
Languages : en
Pages : 822
Book Description
Journal of Propulsion and Power
Author: Progress in Hybrid RANS-LES Modelling
Author: Song FuPublisher: Springer Science & Business Media
ISBN: 3642318185
Category : Technology & Engineering
Languages : en
Pages : 508
Book Description
The present book contains contributions presented at the Fourth Symposium on Hybrid RANS-LES Methods, held in Beijing, China, 28-30 September 2011, being a continuation of symposia taking place in Stockholm (Sweden, 2005), in Corfu (Greece, 2007), and Gdansk (Poland, 2009). The contributions to the last two symposia were published as NNFM, Vol. 97 and Vol. 111. At the Beijing symposium, along with seven invited keynotes, another 46 papers (plus 5 posters) were presented addressing topics on Novel turbulence-resolving simulation and modelling, Improved hybrid RANS-LES methods, Comparative studies of difference modelling methods, Modelling-related numerical issues and Industrial applications.. The present book reflects recent activities and new progress made in the development and applications of hybrid RANS-LES methods in general.
Control of Cavity Resonance Using Steady and Oscillatory Blowing
Author: National Aeronautics and Space Administration (NASA)Publisher: Createspace Independent Publishing Platform
ISBN: 9781720452690
Category :
Languages : en
Pages : 36
Book Description
An experimental study to investigate the effect of steady and oscillatory (with zero net mass flux) blowing on cavity resonance is undertaken. The objective is to study the basic mechanisms of the control of cavity resonance. An actuator is designed and calibrated to generate either steady blowing or oscillatory blowing with A zero net mass flux. The results of the experiment show that both steady and oscillatory blowing are effective, and reduce the amplitude of the dominant resonant mode by 1OdB. The oscillatory blowing is however found to be more superior in that the same effectiveness could be accomplished with a momentum coefficient an order of magnitude smaller than for steady blowing. The experiment also confirms the results of previous computations that suggest the forcing frequency for oscillatory blowing must not be at harmonic frequencies of the cavity resonant modes.Lamp, Alison M. and Chokani, NdaonaLangley Research CenterSTEADY FLOW; BLOWING; NOISE REDUCTION; JET AIRCRAFT NOISE; AIRFRAMES; CAVITY FLOW; WIND TUNNEL TESTS; OSCILLATING FLOW; CALIBRATING; BAYS (STRUCTURAL UNITS); BLOWDOWN WIND TUNNELS
Model-based Feedback Control of Cavity Resonance
Author: Clarence W. RowleyPublisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 60
Book Description
This report presents results of experiments and numerical simulations studying closed-loop feedback control of oscillations in the compressible flow past a rectangular cavity. When weapons bays are exposed to high flow speeds, extremely large pressure fluctuations result, and are often large enough to cause structural damage to the aircraft and internal stores. The goal of this work is to design an implement a model-based feedback controller to suppress oscillations in the flow past a cavity over a range of operating conditions, using much less power than open-loop techniques; and to understand the physics well enough to allow the techniques to be reliably transferred to full-scale aircraft. Several specific advances have been made in this work, relevant for cavity flow control as well as for other closed-loop flow control applications. Theoretical models are presented for temporally developing shear layers and cavity oscillations at the flow conditions used in both simulations and experiments. These models can be used to construct dynamic observers, which reconstruct the full flow information from a limited number of sensors, and significantly outperform static estimators such as Linear Stochastic Estimation (LSE).
41st AIAA Aerospace Sciences Meeting & Exhibit
Author: IUTAM Symposium on Mechanics of Passive and Active Flow Control
Author: G.E.A. MeierPublisher: Springer Science & Business Media
ISBN: 9401141991
Category : Technology & Engineering
Languages : en
Pages : 397
Book Description
The call for papers for the rUTAM-Symposium on Mechanics of Passive and Active Flow Control brought an overwhelming response of applications for contributions. Fi nally 12 invited lectures, 48 papers and 23 posters were selected by thc Scientific Com mittee to be presented in the conference. 58 papers are published in this volume. Due to the limited number of pages available, poster presentations could not be considered for publication. The editors would like to thank all the members of the Scientific Committee for their very valuable assistance. The papers presented at the rUT AM Symposium were classified under three groups de voted to • Passive Control Methods, • Active Control Methods and • Control Concepts. This was done to contrast at first between the passive techniques where the control power is mainly supplied by the flow itself and the active techniques where the power is pro vided by external sources; the third group was devoted to control concepts for presenting methods of control theory and new techniques of flow control.
30th AIAA Fluid Dynamics Conference
Author: AIAA Journal
Author: American Institute of Aeronautics and AstronauticsPublisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1112
Book Description
Author: 
Author: