Effect of inlet vanes on centrifugal compressor acoustics and performance

Figurella, Neil; Dehmer, Rick; Selamet, Ahmet; Tallio, K. V.; Miazgowicz, Keith; Wade, Robert; Karim, Ahsanul; Keller, Philip; Shutty, John

doi:10.3397/1/376223

Cited by 21 publications

(10 citation statements)

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“…The acoustic spectrum of the compressor operating near surge is characterised specifically by broadband noise identified with the onomatopoeia like 'whoosh' [4,5] or 'hiss' [6] or 'blow' [7] noise. Literature shows varied values when it comes to frequency range of the 'whoosh' noise ranging from 1.5 -3 kHz [7,5] to 4 -12 kHz [8,4]. Torregrosa et al [9] points towards the conflation with the so called Tip Clearance Noise (TCN) by the authors [8,4] identifying an inclusive range of 'whoosh' noise.…”

Section: Introductionmentioning

confidence: 99%

“…Literature shows varied values when it comes to frequency range of the 'whoosh' noise ranging from 1.5 -3 kHz [7,5] to 4 -12 kHz [8,4]. Torregrosa et al [9] points towards the conflation with the so called Tip Clearance Noise (TCN) by the authors [8,4] identifying an inclusive range of 'whoosh' noise. Earlier studies [4,5] identified 'whoosh' noise as a specific near surge or marginal surge phenomenon but recent literature [10,11] shows the presence of broadband noise at design conditions too.…”

Section: Introductionmentioning

confidence: 99%

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Acoustic and pressure characteristics of a ported shroud turbocompressor operating at near surge conditions

et al. 2019

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The operation of compressor at lower mass flow rates is limited by surge which is marked by large fluctuations in operational variables and accompanied by significant increase in noise. Ported shroud casing treatment is a widely used method to control the flow near unstable conditions in order to obtain a stable operation and enhance deep surge margin. The research on the acoustic effects of the ported shroud design is limited. Therefore, this paper numerically characterises the acoustic features of a turbocharger compressor with ported shroud design operating at marginal or soft surge conditions and investigates the correlation between acoustic characteristics and the spatial flow structures. The acoustic and the flow field features are analysed using spectral signatures obtained from an experimentally validated numerical model using both performance and acoustic measurements. Propagation of the frequency content through the ducts has been estimated with the aid of the beamforming and method of characteristics to enhance the content coming from the compressor. Expected acoustic phenomena such as rotating order tones and blade passing peaks are correctly identified in the modelled spectrum with the limitation to capture the specific broadband features. Hence, the numerical model can be used to further the research encompassing the impact these flow enhancement solutions have on the noise emission of the turbocharger. Inspection of the flow field shows radially exiting fluid at the ported shroud slot leading to the formation of the high-speed jets exiting the ported shroud cavity. Circumferential propagation of the stall cells is also identified in the impeller. Further inspection of the pressure field through modal decomposition implies the localisation of the energetic noise sources in the impeller downstream components. The influence of the ported shroud cavity on the acoustic characteristic of the compressor is not significant and is limited to the propagation of the tonal noise in the direction of impeller upstream.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Acoustic and pressure characteristics of a ported shroud turbocompressor operating at near surge conditions

et al. 2019

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“…The tonal features include Rotating Order (RO) 1 or 'buzz-saw' tones [14] and Blade Pass Frequency (BPF) 2 while broadband noises are identified as the onomatopoeic 'whoosh' noise [4,7,20] observed within the plane wave range and Tip Clearance Noise (TCN) [13] present outside the plane wave range. Some authors [21,22] seem to conflate these two broadband features into a single inclusive broadband but they appear to be two different phenomena. The lower frequency 'whoosh' noise can be identified within 1-4 kHz range while TCN is usually seen at higher frequencies before the BPF of the compressor.…”

Section: Introductionmentioning

confidence: 99%

Acoustic characterisation of a small high-speed centrifugal compressor with casing treatment: An experimental study

Sharma

Broatch

García-Tíscar

et al. 2019

Aerospace Science and Technology

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With the advancements in manufacturing, materials and computational methods, turbomachinery designs have become more efficient providing higher specific power and reliability with lower weight and cost. The rotational speed of turbomachines has increased while the overall machine size has decreased for a similar power output leading to the pervasive presence of small, high-speed turbomachines, specifically centrifugal compressors in helicopters, unmanned aerial vehicles (UAVs), auxiliary power units (APUs), turbochargers and micro gas turbines. In addition to superior aerodynamic performance over a wide range, increased operating speeds have made the acoustic emissions of small centrifugal compressors a critical aspect of design. Therefore, this work presents an experimental campaign to characterise the acoustic behaviour of a compressor with an intent to quantify the dominant features of the flow-induced noise for design and near surge operating conditions. Furthermore, the campaign is extended to establish the impact of the ported shroud casing treatment and operating speed on the acoustic emission of the compressor. The induct noise measurement method is used in this work to quantify the noise generated in the compressor by measuring pressure fluctuations near the inducer and diffuser while the propagation of the generated noise to the ducts is computed from an array of piezoelectric sensors. Spectra at the design operating point are dominated by tonal noise while broadband noise content is the dominant feature of spectra for near surge operation. Although the ported shroud cavity does not significantly alter the overall noise levels of the compressor operating at design condition, it does seem to propagate tonal noise. For near surge operation, the casing treatment positively impacts the acoustic emission with a reduction of approximately 10 dB in the range up to the blade pass frequency. Furthermore, various broadband features are also observed to be alleviated by the casing treatment.

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“…21 Different from the EGVs, IGVs have also been an option to improve the performances of turbo-machinery, such as fans, compressors, and pumps. 19,22–25 Using a pre-swirl inlet flow, the IGVs may also enlarge the operating regime of stability and be suitable over a more expansive set of conditions. Investigations into the effects of IGVs on pumps have shown that IGVs can decrease the maximum amplitudes of pressure fluctuations on the blade leading edge 25 and improve the cavitation performance of the pump.…”

Section: Introductionmentioning

confidence: 99%

Performance improvement of an axial-flow pump with inlet guide vanes in the turbine mode

Zhao¹,

Guo²,

Cheng

2019

Proceedings of the Institution of Mechanical Engineers, Part A:

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The axial pump operating in the pump-as-turbine mode is a practical and cost-saving alternative suitable for low-head pico hydropower in rural and remote areas that bypasses the need for expensive turbines. Their pump characteristics, however, indicate that efficiency is low in off-design flow rates. Using the computational fluid dynamics, the adjustable inlet guide vanes with five angles (±20°, 0°, ±10°) in front of the impeller of the axial pump have been redesigned and installed specifically to increase the operating range of high efficiency in the pump-as-turbine mode. To validate the simulation method, a prototype of the axial pump was built to measure in the pump mode the pump characteristics including head and efficiency. The results obtained show that the computational fluid dynamics calculated results are in qualitative agreement with the experimental data. In the pump-as-turbine mode, the adjustable inlet guide vanes were found to affect the performance of the axial pump. The most important aspect is that the adjustable inlet guide vanes widen the efficiency range if the inlet guide vane angle is adjusted for different flow rates. For the same situation with negative angles, the efficiency values at the BEP are higher than those with positive angles, where the efficiency around the angle − 10° is the highest. The main reason is that the direction of flow at the impeller-zone exit is guided by the adjustable inlet guide vanes to reduce the energy loss, which can be supported in the view of vector field and energy losses of different parts of pump.

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Effect of inlet vanes on centrifugal compressor acoustics and performance

Cited by 21 publications

References 0 publications

Acoustic and pressure characteristics of a ported shroud turbocompressor operating at near surge conditions

Acoustic and pressure characteristics of a ported shroud turbocompressor operating at near surge conditions

Acoustic characterisation of a small high-speed centrifugal compressor with casing treatment: An experimental study

Performance improvement of an axial-flow pump with inlet guide vanes in the turbine mode

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