Study of Underexpanded Sonic Jets by Numerical Simulation

Thanigaiarasu, S.; Karthick, R Rangadurai; Arunprasad, R.; SyedMusthafa, H.; Elangovan, S.; Rathakrishnan, E.

doi:10.1515/tjj-2012-0023

Cited by 8 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Steffen et al [19] compared numerical results with corresponding experimental re sults and noted good agreement in terms of the vortices field as well as overall jet entrainment. There is also a recent paper by Thanigaiarasu et al [20] regarding the nu merical simulation of under expanded sonic jets. These re sults lent further credence to the postulations made on the basic flow dynamics as discussed above.…”

Section: Literature Reviewmentioning

confidence: 99%

“…The centerline pressure decay is an authentic measure of jet propagation (Lovaraju and Rathakrishnan [20]) that is, faster the decay, the faster is the jet mixing with the en trained fluid mass. Since velocity and pressure variation are supposed to be synonymous at lower subsonic speeds, the centerline velocity decay can clearly show the extent of jet core, which is defined as the axial extent up to which the nozzle exit velocity prevails for subsonic jets and the axial extent up to which supersonic flow prevails for su personic jets.…”

Section: Numerical Study For All Three Types Of Jet At 04 Machmentioning

confidence: 99%

See 1 more Smart Citation

Study of Slanted Perforated Jets

Ahmed¹,

Thanigaiarasu²,

Santhosh³

et al. 2013

Int. J. Turbo Jet-Engines

Self Cite

View full text Add to dashboard Cite

This paper presents the numerical simulation of the subsonic jets controlled by slanted perforated tabs and its performance of mixing efficiency is compared with the jet controlled by solid tab and free jet. The objective of this paper is to study the performance of slanted per foration geometry tabs in controlling high speed jets to enhance the mixing of jet with the ambient air, to sup press the noise level and to minimize the thrust loss. In this paper the simulations have been carried out using the commercial meshing and analysis software. Due to the effect of tabs the potential core decay occurs and velocity reduces drastically because of enhanced mixing produced by the tabs. From the results it is found that in slanted per forated tab the main jet interacts with the slanted perfo rated jet which causes in effective mixing, instability in jets and lower thrust loss when compared with the free jet. The decay of the potential core and velocity reduction is computed by simulation for 0.4 Mach number. Velocity plots are obtained at both near field and far field down stream locations to study the jet distortion with slanted perforated tabs and solid tabs. The results obtained for perforated tabs for 0.4 Mach number are also compared with various other Mach numbers. They have also been validated with experimental results which show good agreement with the computational results.

show abstract

Section: Literature Reviewmentioning

confidence: 99%

Section: Numerical Study For All Three Types Of Jet At 04 Machmentioning

confidence: 99%

Study of Slanted Perforated Jets

Ahmed¹,

Thanigaiarasu²,

Santhosh³

et al. 2013

Int. J. Turbo Jet-Engines

Self Cite

View full text Add to dashboard Cite

show abstract

“…The jet flow field was first calculated in steady state to obtain the initial steady-state flow field. The steady state turbulence calculations were carried out in the realizable k-ε turbulence model [20]. Then, the transient calculations were carried out in LES turbulence model and the jet noise field was calculated by the Ffowcs Williams and Hawkings equation.…”

Section: Calculation Methods and Governing Equationsmentioning

confidence: 99%

Minimum Quantity Lubrication Jet Noise: Passive Control

Hu,

Yu,

et al. 2023

Micromachines

View full text Add to dashboard Cite

Jet noise is a common problem in minimum quantity lubrication (MQL) technology. This should be given great attention because of its serious impacts on the physical and mental health of the operators. In this study, a micro-grooved nozzle is proposed based on the noise reduction concept of biological micro-grooves. The flow field and acoustic characteristics of an original nozzle and a micro-grooved nozzle were investigated numerically to help better understand the noise reduction mechanism. The reasons for noise generation and the effects of the length (L), width (W) and depth (δ) of the micro-grooves on noise reduction were analyzed. It was found that jet noise is generated by the large-scale vortex ring structure and the pressure fluctuations caused by its motion. The overall sound pressure level (OASPL) decreased with the increases in W and δ, and increased with the increase in L. Among of them, δ has the greatest effect on noise reduction. The maximum noise reduction achieved was 6.66 dB, as verified by the OASPL test. Finally, the noise reduction mechanism was discussed in terms of the flow field, vorticity and the frequency characteristics. Micro-grooves can enhance the mixing of airflow inside the nozzle and accelerate the process of large-scale vortices breaking into smaller-scale vortices. It also reduces the sound pressure level (SPL) of middle frequencies, as well as the SPL of high frequencies on specific angles.

show abstract