A5031801765- Aerodynamics and Acoustics in Jet Flows
- Fluid Dynamics and Turbulent Flows
- Wind and Air Flow Studies
- Plasma and Flow Control in Aerodynamics
- Computational Fluid Dynamics and Aerodynamics
- Particle Dynamics in Fluid Flows
- Acoustic Wave Phenomena Research
- Hydrology and Sediment Transport Processes
- Heat Transfer Mechanisms
- Fluid Dynamics and Heat Transfer
- Noise Effects and Management
- Fluid Dynamics Simulations and Interactions
- Combustion and flame dynamics
- Heat Transfer and Optimization
- Aerodynamics and Fluid Dynamics Research
- Laser-Plasma Interactions and Diagnostics
University of Cambridge
2012-2021
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2021
Defence Academy of the United Kingdom
2021
Cranfield University
2021
Indian Institute of Technology Madras
2008
This paper investigates numerically the acoustic sources and far-field noise of chevron round jets. The are described by fourth-order space–time velocity cross correlations, which calculated based on a large-eddy simulation flowfield. Gaussian functions found to fit axial, radial, azimuthal correlations reasonably well. axial length scales three four times radial scales. For jet, cross-correlation vary with angle up six jet diameters downstream; beyond that, they become axisymmetric like...
This study develops a jet-noise-prediction model for chevrons and microjets. A novel equation is proposed to express the amplitude of fourth-order space-time velocity cross correlations, which represent sources noise emanated from unheated jets, in terms mean-flow parameters turbulence statistics, such as streamwise circulation, axial velocity, turbulent kinetic energy. The correlations based on Reynolds-averaged Navier-Stokes flowfield showed good agreement with those large-eddy-simulation...
Jet noise has been a major community concern since the 1940s. Among noise-suppression devices, chevron nozzles are most effective as they significantly reduce low-frequency without appreciable thrust loss. The objective is to understand mechanisms of by identifying sources and predicting far-field for both round jets. To identify sources, fourth-order space-time velocity cross-correlations calculated based on an LES flow field. Gaussian form fits axial, radial azimuthal reasonably well....
Abstract This article addresses the challenges of assessing pedestrian-level wind conditions in urban environments using a deep learning approach. The influence large buildings on patterns has significant implications for thermal comfort, pollutant transport, pedestrian safety, and energy usage. Traditional methods, such as tunnel testing, are time-consuming costly, leading to growing interest computational methods like fluid dynamics (CFD) simulations. However, CFD still requires time...
This study develops a single-stream jet noise prediction model for family of chevron nozzles. An original equation is proposed the fourth-order space-time cross-correlations. They are expressed in flow parameters such as streamwise circulation and turbulent kinetic energy. The cross-correlations based on Reynolds Averaged Navier-Stokes (RANS) flowfield showed good agreement with those Large Eddy Simulation (LES) flowfield. proves that describes accurately. With this novel source description,...
An experimental investigation was carried out to compare active and passive flow control of an incompressible axisymmetric jet. For control, the lip circular jet equipped with a single small flap deflected away from stream at angle 30°. The incorporated slot through which steady suction oscillatory were implemented. triangular tab into Both chord lengths one sixth diameter. momentum increased in case by entraining ambient fluid, whereas decreased control. effect saturated for volumetric...
An experimental investigation was conducted to compare the active generation and management of streamwise vortices in an incompressible jet flow using different control methods. The lip equipped with a small flap deflected away from stream at angle 30°, that incorporated slot through which steady suction, oscillatory suction zero mass-flux perturbations were introduced. Data acquired compared on basis momentum addition jet, vorticity turbulent stresses. All methods produced increase...
© 2014, American Institute of Aeronautics and Astronautics Inc. All rights reserved. This study applies a low-order jet noise prediction model, which was originally developed established for chevrons (Depuru Mohan & Dowling1), to microjets. With the novel source description, there is an excellent agreement between our model's far-field predictions measurements wide range frequencies observer angles. As model quick accurate, parametric performed investigate effect microjets on noise. The...