On the unsteady dynamics of partially shrouded compressible jets

Nanda, Soumya Ranjan; Karthick, S. K.; Krishna, T. V.; De, Ashoke; Ibrahim, Mohammed S.

doi:10.1007/s00348-021-03318-0

Cited by 7 publications

(1 citation statement)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Figure 14 a-b, cumulative energy contents of the ranked modes 70,71 are shown for the variations in θ and ξ . The dominant mode (k = 1) contains roughly 20% of the total energy in the fluid domain in θ variation cases (Figure 14a).…”

Section: F Spatiotemporal Modesmentioning

confidence: 99%

Unsteady dynamics in a subsonic duct flow with a bluff body

George,

Karthick,

Srikrishnan

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

A series of reduced-order numerical simulations on a specific bluff body type (v-gutters) in a subsonic duct flow is done to assess the unsteady wake dynamics. Two of the v-gutter's geometrical parameters are varied: the v-gutter's base angle (θ ) and the size of a slit (ξ ) at the leading-edge of the v-gutter. Turbulent flow kinematics and pressure field are analyzed to evaluate the unsteadiness at a freestream Mach number of M ∞ = 0.25 and a freestream Reynolds number based on bluff body's transverse length (L) of Re L = 0.1 × 10 6 . Five v-gutter angles are considered (θ , • = π/6, π/4, π/3, 5π/12, π/2) and three slit sizes (ξ , mm =0,0.25,0.5) are considered only for a particular θ = [π/6]. In general, high fluctuations in velocity and pressure are seen for the bluffest body in consideration (θ = π/2) with higher drag (c d ) and total pressure loss (∆p 0 ). However, bluffer bodies produce periodic shedding structures that promote flow mixing. On the other hand, the presence of a slit on a streamlined body (θ = π/6) tends to efficiently stabilize the wake and thus, producing almost a periodic shedding structure with lower c d and ∆p 0 . For θ = [π/6], broadened spectra in vortex shedding is seen with a peak at [ f L/u ∞ ] ∼ 0.08. For θ ≥ [π/4], a dominant discrete shedding frequency is seen with a gradual spectral decay. Similarly, the effects of ξ on the θ = [π/6] case produce a discrete shedding frequency instead of a broadened one, as told before. The shedding frequency increases to a maximum of [ f L/u ∞ ] ∼ 0.26 for the maximum slit size of ξ = 0.5. From the analysis of the x − t diagram and the modal analysis of vorticity and velocity magnitude in the wake, the peaks are indeed found to agree with the spectral analysis. More insights on the shedding vortices, momentum deficit in the wake, varying energy contents in the flow field, and the dominant spatiotemporal structures are also provided.

show abstract

Section: F Spatiotemporal Modesmentioning

confidence: 99%

Unsteady dynamics in a subsonic duct flow with a bluff body

George,

Karthick,

Srikrishnan

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

Unsteadiness in hypersonic leading-edge separation

2023

View full text Add to dashboard Cite

Unsteady dynamics in a subsonic duct flow with a bluff body

et al. 2022

View full text Add to dashboard Cite

A series of reduced-order numerical simulations on a specific bluff body type (v-gutters) in a subsonic duct flow is done to assess the unsteady wake dynamics. Two of the v-gutter's geometrical parameters are varied: the v-gutter's base angle (θ) and the size of a slit (ξ) at the leading edge of the v-gutter. Five v-gutter angles are considered (θ,{degree sign} = π/6, π/4, π/3, 5π/12, π/2) and three slit sizes (ξ, mm =0,0.25,0.5) are considered only for a particular θ = [π/6]. High fluctuations in velocity and pressure are seen for the bluffest body in consideration (θ = π/2) with higher drag (cd) and total pressure loss (Δp0). On the other hand, the presence of a slit on a streamlined body (θ = π/6) tends to efficiently stabilize the wake and thus, producing almost a periodic shedding structure with lower cd and Δp0. For θ = [π/6], broadened spectra in vortex shedding are seen with a peak at [fL/u∞] ∼ 0.08. For θ {greater than or equal to} [π/4], a dominant discrete shedding frequency is seen with a gradual spectral decay. Similarly, the effects of ξ on the θ = [π/6] case produce a discrete shedding frequency instead of a broadened one, as told before. The shedding frequency increases to a maximum of [fL/u∞] ∼ 0.26 for the maximum slit size of ξ = 0.5. More insights on the shedding vortices, momentum deficit in the wake, varying energy contents in the flow field, and the dominant spatiotemporal structures are also provided.

show abstract

On the unsteady dynamics of partially shrouded compressible jets

Cited by 7 publications

References 53 publications

Unsteady dynamics in a subsonic duct flow with a bluff body

Unsteady dynamics in a subsonic duct flow with a bluff body

Unsteadiness in hypersonic leading-edge separation

Unsteady dynamics in a subsonic duct flow with a bluff body

Contact Info

Product

Resources

About