Simulation of HVAC flow noise sources with an exit vent as an example

Saarinen, Pekka; Siikonen, Timo

doi:10.1080/14733315.2016.1173292

Cited by 4 publications

(4 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 18 shows the acoustic source terms obtained from the CFD solution on the cut plane y = 0 utilizing different turbulence models in wetted conditions. As shown by Saarinen and Siikonen [56], the divergence of the divergence of the Lighthill tensor, or the source term of the acoustic wave equation, can in incompressible cases be simplified to ∇ We can see that in the wetted case, the acoustic source term distribution was more concentrated and regular near the hub vortex than in the cavitating case. In the cavitating case, the source distribution was spread to a slightly wider radius in the wake.…”

Section: Wake Flow Structuresmentioning

confidence: 68%

DDES of Wetted and Cavitating Marine Propeller for CHA Underwater Noise Assessment

Viitanen

Hynninen

Sipilä

et al. 2018

JMSE

Self Cite

View full text Add to dashboard Cite

In this paper we present results of delayed detached eddy simulation (DDES) and computational hydroacoustics (CHA) simulations of a marine propeller operating in a cavitation tunnel. DDES is carried out in both wetted and cavitating conditions, and we perform the investigation at several propeller loadings. CHA analyses are done for one propeller loading both in wetted and cavitating conditions. The simulations are validated against experiments conducted in the cavitation tunnel. Propeller global forces, local flow phenomena, as well as cavitation patterns are compared to the cavitation tunnel tests. Hydroacoustic sources due to the propeller are evaluated from the flow solution, and corresponding acoustic simulations utilizing an acoustic analogy are made. The propeller wake flow structures are investigated for the wetted and cavitating operating conditions, and the acoustic excitation and output of the same cases are discussed.

show abstract

Section: Wake Flow Structuresmentioning

confidence: 68%

DDES of Wetted and Cavitating Marine Propeller for CHA Underwater Noise Assessment

Viitanen

Hynninen

Sipilä

et al. 2018

JMSE

Self Cite

View full text Add to dashboard Cite

show abstract

“…In case of nonhomogeneous EE solutions, the velocities of each phase U φ are solved individually; in case of two phases, such as liquid l and gas g, the Lighthill tensor reads T = α l ρ l U l U l + α g ρ g U g U g . Moreover, following Saarinen and Siikonen [68], for incompressible flows, the forcing term of Equation (15), namely ∇ • ∇ • T, can be directly related to the Q-criterion, which is the second invariant of the velocity gradient tensor ∇U, by the relation ∇…”

Section: Hydroacousticsmentioning

confidence: 99%

Multiphase Flow Simulation of ITTC Standard Cavitator for Underwater Radiated Noise Prediction

Hynninen

Viitanen

Tanttari

et al. 2023

JMSE

View full text Add to dashboard Cite

This work focuses on the main issues related to noise measurements in cavitation tunnels. The scope of the paper is to twofold: to obtain a better understanding on the main phenomena underlying experiments and to define consistent cavitation tunnel measurement corrections for background noise, wall reflections, and distance normalisation. To this aim, the acoustic field generated by the ITTC standard cavitator model inside a cavitation tunnel is predicted by Lighthill’s acoustic analogy and solved through a finite element method that inherently accounts for the presence of the walls. Sources of sound detection relies on two multiphase CFD solvers, namely, the homogeneous mixture model—Volume of Fluid method and the Euler–Euler formulations. Starting from the computation of the sound pressure level in the free field with the assumption of spherical spreading without absorption, corrections from losses and spreading are detected by the above approach. Background-corrected sound pressure levels are identified and then compared with the source levels measured in the cavitation tunnel of the Potsdam Model Basin (SVA). It is found that free-field computations corrected by tunnel-induced effects match well with experiments up to 100 Hz (in the one-third octave band), whereas relevant discrepancies arise out of this range that need further investigations.

show abstract

“…Figure 18 shows the acoustic source terms obtained from the CFD solution on the cut plane y = 0 utilizing different turbulence models in wetted conditions. As shown by Saarinen and Siikonen [56], the divergence of the divergence of the Lighthill tensor, or the source term of the acoustic wave equation, can in incompressible cases be simplified to ∇•(∇• Tij )=S inc = −2ρQ (kg/m 3 s 2 ), where Q is the second invariant of the velocity gradient tensor. Figure 19 furthermore shows the acoustic source terms, obtained from the CFD solution, on the plane x/D = 0.5 for the wetted and cavitating cases.…”

Section: Acoustic Excitationsmentioning

confidence: 99%

Marine Propulsors

2018

View full text Add to dashboard Cite

Marine propulsors are key components of the many thousands of ships operating in oceans, lakes, and rivers around the world. The performance of propulsors are vital for the efficiency, environmental impact and safety of the ships. Propulsor performance is also important for crew and passenger comfort. New types of propulsors, with electric drives, flexible blades, and multi-stage propellers require new knowledge and improved tools. Innovative main or auxiliary propulsor types, using renewable energy from waves or winds, are also being commercialized. The improvement of computers and computational fluid dynamics creates new opportunities for advanced design and performance prediction, and new instrumentation and data collection techniques enable more advanced experimental techniques. This book is devoted to bringing the latest developments in research and technical developments regarding the hydrodynamic aspects of marine propulsors, to the benefit of both academics and industry. It consist of 16 peer-reviewed scientific papers previously published in the Journal of Marine Science and Engineering. Twelve of these papers are improved and extended versions of papers presented at the Fifth Symposium of Marine Propulsors in June 2017 in Espoo, Finland, while the remaining four are completely new submissions. The Symposia of Marine Propulsors are held bi-annually, the next one will take place in Rome in May 2019.

show abstract

Simulation of HVAC flow noise sources with an exit vent as an example

Cited by 4 publications

References 14 publications

DDES of Wetted and Cavitating Marine Propeller for CHA Underwater Noise Assessment

DDES of Wetted and Cavitating Marine Propeller for CHA Underwater Noise Assessment

Multiphase Flow Simulation of ITTC Standard Cavitator for Underwater Radiated Noise Prediction

Marine Propulsors

Contact Info

Product

Resources

About