Related papers: Acoustic Black Hole Damper for Thermoacoustic Inst…
Acoustic dampers are efficient and cost-effective means for suppressing thermoacoustic instabilities in combustion chambers. However, their design and the choice of their purging air mass flow is a challenging task, when one aims at…
An acoustic black hole (ABH) consists of a tapered structure whose thickness follows a power-law profile. When attached to a host structure, an ABH localizes and traps the vibrational energy, which can then be dissipated through, e.g., a…
Acoustic black hole (ABH) structure has been extensively employed in applications such as vibration mitigation, noise reduction, and energy harvesting, owing to its unique sound wave trapping and energy concentration effects. Furthermore,…
This study demonstrates the stabilization of a sequential combustor with Nanosecond Repetitively Pulsed Discharges (NRPD). A constant pressure sequential combustor offers key advantages compared to a conventional combustor, in particular, a…
The onset of thermoacoustic instabilities in lean-premixed gas-turbine combustors is a crucial problem leading to degradation in engine and emissions performance and shortened component life. The main aim of this study is to propose a…
Advancements in combustion technologies are often impeded by complex combustion dynamics. Active control has proven effective at mitigating these dynamics in the lab, but mass adoption requires more affordable, lightweight, and reliable…
This work studies the effectiveness of acoustic black holes to generate broadband non-reflective traveling waves using a single excitation source. This is inspired by similar observations in the basilar membrane of the mammalian inner ear.…
This experimental study investigates the dynamical transition from stable operation to thermoacoustic instability in a turbulent bluff-body stabilized dump combustor. We conduct experiments to characterize the dynamical transition utilizing…
Thermoacoustic instabilities in gas turbines and aeroengine combustors falls within the category of complex systems. They can be described phenomenologically using nonlinear stochastic differential equations, which constitute the grounds…
Acoustic analogues of Kerr black hole in plasmas are considered, by taking for granted the existence of acoustic ion waves in plasmas. An effective black holes (BH) in curved Riemannian spacetime in a random walk plasmas is endowed with a…
The impact of thermodiffusive effects on combustion noise in turbulent premixed slot jet flames is investigated using Direct Numerical Simulations. Two thermodiffusively unstable lean hydrogen-air flames are compared with a…
In this work, the thermo-acoustic instabilities of a gas turbine model combustor, the so-called SFB606 combustor, are numerically investigated using Large Eddy Simulation (LES) combined with tabulated chemistry and Artificial Thickened…
Predictions of thermoacoustic instabilities in annular combustors are essential but difficult. Axial variations of flow and thermal parameters increase the cost of numerical simulations and restrict the application of analytical solutions.…
In this study, we explore the thermodynamic properties of a Schwarzschild black hole (BH) embedded in an anti-de Sitter (AdS) background, which is further coupled with a cloud of strings and surrounded by a quintessence-like fluid.…
We investigate the thermodynamic behavior of a spherically symmetric Anti-de Sitter black hole in Mod(A)Max electrodynamics surrounded by a cloud of strings. Within the extended phase-space framework, we treat the cosmological constant as a…
We studied the process of decoherence induced by the presence of an environment in acoustic black holes, using the open quantum system approach, thus extending previous work. We focused on the ion trap model but the formalism is general to…
Thermoacoustic Refrigerators use acoustic power for generating cold temperatures. Development of refrigerators based on the thermoacoustic technology is a novel solution to the present day need of cooling, without causing environmental…
This paper presents an experimental study of the influence of heat losses on the onset of thermoacoustic instabilities in methane-air premixed flames propagating in a horizontal tube of small diameter, $D = 10$ mm. Flames are ignited at the…
Assigning homogeneous boundary conditions, such as acoustic impedance, to the thermoviscous wave equations (TWE) derived by transforming the linearized Navier-Stokes equations (LNSE) to the frequency domain yields a so-called Helmholtz…
We propose a framework of Lagrangian Coherent Structures (LCS) to enable passive open-loop control of tonal sound generated during thermoacoustic instability. Experiments were performed in a laboratory-scale bluff-body stabilized turbulent…