Results 71 to 80 of about 103,692 (197)

Acoustic Design Parameter Change of a Pressurized Combustor Leading to Limit Cycle Oscillations

Energies
When aiming to cut down on the emission of nitric oxides by gas turbine engines, it is advantageous to have them operate at low combustion temperatures. This is achieved by lean premixed combustion.
Mehmet Kapucu, Jim B. W. Kok, Artur K. Pozarlik   +2 more
doaj   +1 more source

Detached Eddy Simulation (DES) of a Turbulent Premixed Flame Stabilized on a Bluff Body

Proceedings in Applied Mathematics and Mechanics, Volume 25, Issue 2, June 2025.
ABSTRACT As the demand for net‐zero emissions intensifies, low‐emission fuels (LEFs) are increasingly explored for their potential to reduce pollutants in combustion systems. The present study investigates the flame dynamics and pollutant emissions (CO and NOx) of different LEFs using detached eddy simulations (DES), a method that offers better ...
Abdelkader Hemaizia, Dominique Thévenin, Cheng Chi   +2 more
wiley   +1 more source

Experimental and 2D CFD study of thermoacoustic instabilities

Journal of Thermal Engineering
Thermoacoustic instability, caused by the interaction of unsteady heat release and acoustic waves, is a significant challenge in combustion systems such as gas turbines and aero engines.
Suchita K. Kadam, Nilaj N. Deshmukh
doaj   +1 more source

The effect of the flame phase on thermoacoustic instabilities [PDF]

Combustion and Flame, 2018
This theoretical paper concerns the influence of the phase of the heat release response on thermoacoustic systems. We focus on one pair of degenerate azimuthal acoustic modes, with frequency ω0. The same results apply for an axial acoustic mode. We show how the value φ0 and the slope −τ of the flame phase at the frequency ω0 affects the boundary of ...
Giulio Ghirardo, Matthew P. Juniper, Mirko R. Bothien   +2 more
openaire   +1 more source

Adaptive Vibration Control of the Moving Cage in the 4 ×$\times$ 4 Hyperbolic PDE‐ODE Model of the Dual‐Cable Mining Elevator

IET Control Theory &Applications, Volume 19, Issue 1, January/December 2025.
This paper proposes an observer‐based adaptive output‐feedback boundary control to stabilize the vibrations of the moving cage of a dual‐cable mining elevator. This system is comprised of two mechanically jointed winding drums that drive the two cables through the floating sheaves to lift the cage.
Elham Aarabi, Mohammadali Ghadiri‐Modarres, Mohsen Mojiri   +2 more
wiley   +1 more source

Boosting flexible electronics with integration of two‐dimensional materials

InfoMat, Volume 6, Issue 7, July 2024.
The progress was summarized in the flexible electronics empowered by the two‐dimensional materials, including electronic skins (for sweat and temperature sensors), gas sensors, touch pads, nanogenerators for mechanical energy collection, flexible supercapacitors and batteries, transistors and logic circuits, as well as memristors for neuromorphic ...
Chongyang Hou, Shuye Zhang, Rui Liu, Thomas Gemming, Alicja Bachmatiuk, Hongbin Zhao, Hao Jia, Shirong Huang, Weijia Zhou, Jian‐Bin Xu, Jinbo Pang, Mark H. Rümmeli, Jinshun Bi, Hong Liu, Gianaurelio Cuniberti   +14 more
wiley   +1 more source

Fluidic Ultrasound Generation for Non‐Destructive Testing

Advanced Materials, Volume 36, Issue 18, May 2, 2024.
Air‐coupled ultrasound enables material characterization and fault detection for specimens that are very large or do not allow contact with other materials. This study presents a novel fluidic transducer that can withstand harsh environments and generates a high‐amplitude ultrasonic signal without impedance mismatch to air.
Benjamin Bühling, Stefan Maack, Christoph Strangfeld   +2 more
wiley   +1 more source

Acoustic Losses in Cryogenic Hydrogen at Transitions Between Tubes of Different Diameters

Hydrogen
Acoustic oscillations in cryogenic systems can either be imposed intentionally, as in pulse-tube cryocoolers, or occur spontaneously due to Taconis-type thermoacoustic instabilities.
Kian Conroy, Konstantin I. Matveev
doaj   +1 more source

Research on Suppression of Vibration Caused by Combustion Pressure Pulsation in Aircraft Engines

Shock and Vibration, Volume 2024, Issue 1, 2024.
Abnormal high‐energy narrowband signals appeared in the aircraft engine test. By analyzing the characteristics of the vibration signals and the pressure pulsation signals in the measurement point data of the engine, it can be speculated that the abnormal vibration energy of the engine is not related to the operation of rotating parts, which upends a ...
Liang Hong, Chao-Ping Zang, He-Jiong Ji, Qiu-Xia Yu, Yun-Fan Jiang, Lian Shen, Cong Gao   +6 more
wiley   +1 more source

Thermoacoustic Stability Boundaries in the Model Combustion Chamber with a Gas-Centered Swirl Coaxial Injector

International Journal of Aerospace Engineering, 2019
The stability of a combustion chamber with a gas-centered swirl coaxial injector is investigated over a wide range of operating conditions in the aspect of thermoacoustic instabilities. First, flame shapes induced by the injector are analyzed for various
Yong Ho Min, Chae Hoon Sohn, Youngbin Yoon   +2 more
doaj   +1 more source