Kavite akışına ait Rossiter modları incelenmiş ve FW-H Akustik Analoji sonuçları ile karşılaştırılmıştır  FW-H denklemleri geçişli iç yüzey ile 3 boyutlu kavite için incelenmiştir  Türbülansın kavite gürültüsüne etkisi gösterilmiştir

No abstract

SummaryCavity flow research has been ongoing experimentally since the 1940s, especially for weapon bay use in fighter aircraft. Technology advancement has led to the beginning of simulations of experimental studies. The success of these simulations has increased with the emergence of High‐Performance Clusters, and simulation studies have started to take the role of experimental studies. In this paper, an open rectangular, unsteady transonic cavity with a length to depth ratio of 5, Mach number 0.85 and Reynolds number of approximately 6.5 × 106 is simulated using Computational Fluid Dynamics (CFD) on a High‐Performance Cluster. Likewise, cavity door is used to model a real weapon bay. Detached‐Eddy Simulation is used to resolve turbulent properties in the flow domain. Results compatible with experimental data are obtained with OpenFOAM, an open‐source CFD code based on the finite volume method. Additionally, computational costs are given in the clock‐time analysis section, and the necessity of high‐performance clusters for CFD and Computational Aeroacoustics studies is emphasized.

Özet: Sunulan bu çalışmada zamana bağlı sıkıştırılamaz akış alanı ve aerodinamik temelli gürültü iki boyutlu kavite geometrisi için incelenmiştir. İki boyutlu zamana bağlı k-ε türbülans modeli farklı hücum açılı kanat kesiti ve θ-eğimli ön duvar için akış alanı çözümünde kullanılmıştır. Kavite geometrisi için hesaplanan sayısal akış alanı sonuçları deneysel veriler ile karşılaştırılmış ve doğrulanmıştır. Ffowcs William -Hawking (FW-H) Akustik Analojisi zamana bağlı akış alanı sonuçları girdi verisi olarak kullanılıp kavite gürültü seviyesi hesaplanmıştır. Kavite -kanat kesiti etkileşiminde pasif kontrol yöntemlerinin akustik sinyal üzerindeki etkisi çalışılmış ve sonuçlar karşılaştırılmıştır. Kavitekanat kesiti ve pasif kontrol mekanizmaları için elde edilen gürültü seviyeleri farklı konumlara yerleştirilmiş mikrofonlar ile incelenmiş ve akış alanı içinde oluşan zamana bağlı yapıların özellikle 0 -100 Hz aralığında akustik sinyale etkidiği tayin edilmiştir. Aeroacoustic Analysis of Cavity -Airfoil Interaction KeywordsCavity flow, Aeroacoustics, Pasive control, Acoustic analogy Abstract: In this study, unsteady incompressible flow field and aerodynamically generated noise of 2D cavity flows are investigated. In the case of 2D flow fields, unsteady standard k-ε turbulence model is used for flow field to observe for different angle of attack of under different front edge angles. Computed numerical results for cavity are compared and validated with experimental measurement. Unsteady flow fields results are used to compute a cavity noise using Ffowcs William -Hawking (FW-H) Acoustics Analogy. The effect of cavity -airfoil interaction with passive control on the acoustic signal is studied and results are compared.Computed noise levels for cavity -airfoil interaction and passive control mechanism are investigated for microphone which are located at different position and the effect of unsteady flow field structure on acoustic signal especially on the range of 0 -100 Hz are computed.

For the automotive industry, acoustic comfort is of increasing importance. Customer expectations and strong competition in the market play an important role to accelerate vehicle development activities. Although the primary function of HVAC (Heating ventilation and Air-conditioning) is thermal comfort of the occupant during ride; acoustic comfort is also important when it comes to customer satisfaction resulting in overall experience of the vehicle. Hence, prediction of cabin interior noise in the early design stage plays an important role in designing a superior quality product. In this paper, cabin interior noise levels generated by HVAC systems are predicted by using computational 1-D (one dimensional) analysis. 3-D (three dimensional) CAD geometry is designed using SOLIDWORKS and 1-D analysis is done on GT-Suite. Main purpose of this paper is to demonstrate how 1-D simulation can be an aid for a duct designer by predicting the NVH characteristic of HVAC Ducts and continuing the research to shorten the product development timelines.