Aerodynamic noise reduction of fan motor unit of cordless vacuum cleaner by optimal designing of splitter blades for impeller

Kunwoo Kim; Seo-Yoon Ryu; Cheolung Cheong; Seongjin Seo; Cheolmin Jang; Hanshin Seol

doi:10.7776/ASK.2020.39.6.524

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2020 Vol.39, Issue 6 Preview Page Next Page

Research Article

Aerodynamic noise reduction of fan motor unit of cordless vacuum cleaner by optimal designing of splitter blades for impeller 임펠라 스플리터 날개 최적 설계를 통한 무선진공청소기 팬 모터 단품의 공력 소음 저감

30 November 2020. pp. 524-532

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Abstract

In this study, noise radiated from a high-speed fan-motor unit for a cordless vacuum cleaner is reduced by designing splitter blades on the existing impeller. First of all, in order to investigate the flow field through a fan-motor unit, especially impeller, the unsteady incompressible Reynolds-Averaged Navier-Stokes (RANS) equations are numerically solved by using computational fluid dynamic technique. With predicted flow field results as input, the Ffowcs Williams-Hawkings (FW-H) integral equation is solved to predict aerodynamic noise radiated from the impeller. The validity of the numerical methods is confirmed by comparing the predicted sound pressure spectrum with the measured one. Further analysis of the predicted flow field shows that the strong vortex is formed between the impeller blades. As the vortex induces the loss of the flow field and acts as an aerodynamic noise source, supplementary splitter blades are designed to the existing impeller to suppress the identified vortex. The length and position of splitter are selected as design factors and the effect of each design factor on aerodynamic noise is numerically analyzed by using the Taguchi method. From this results, the optimum location and length of splitter for minimum radiated noise is determined. The finally selected design shows lower noise than the existing one.

Keywords

Cordless vacuum cleaner

Aerodynamic noise

Impeller

Splitter

Hybrid computational aeroacoustics

본 논문에서는 무선진공청소기용 팬 모터 단품으로부터 방사되는 공력소음을 저감하기 위하여 팬 모터 단품 내부의 기존 임펠라에 스플리터 날개를 설계하였다. 우선, 팬 모터 단품, 특히 임펠라의 유동장을 분석하기 위하여 전산유체역학 기법을 사용하여 비정상, 비압축성 Reynolds-Averaged Navier-Stokes(RANS) 방정식을 수치적으로 해석하였다. 예측한 유동장 결과를 입력값으로 Ffowcs Williams-Hawkings(FW-H) 적분 방정식을 풀어 임펠라로부터 방사되는 소음을 수치적으로 예측하였다. 예측한 음압스펙트럼과 측정값의 비교를 통하여 수치해석방법의 유효성을 검증하였다. 예측한 유동장 결과에 대한 추가 분석을 통하여 임펠라 날개 사이에서 강한 와류가 형성되는 것을 확인하였다. 와류는 유동에는 손실로 소음에는 소음원으로 작용하기 때문에 기존 임펠라에 스플리터 형상을 추가 설계하여 와류를 억제하고자 하였다. 스플리터의 길이와 위치를 설계 인자로 선정하였으며, 다구찌 기법을 사용하여 각각의 설계 인자가 공력소음에 미치는 영향도를 살펴보았다. 이 결과로부터 최소소음을 나타내는 스플리터의 최적 위치와 길이를 결정하였다. 최종 선정된 설계안에 대한 추가 해석을 통하여 소음성능이 개선됨을 확인 하였다.

키워드

무선진공청소기

공력소음

임펠라

스플리터

복합전산공력음향학

References

S. Lee, S. Heo, and C. Cheong, "Prediction and reduction of internal blade-passing frequency noise of the centrifugal fan in a refrigerator," IJR. 33, 1129- 1141 (2010). 10.1016/j.ijrefrig.2010.03.006

S. Heo, C. Cheong, and T.-H. Kim, "Unsteady fast random particle mesh method for efficient prediction of tonal and broadband noises of a centrifugal fan unit," AIP Advances, 5, 097133 (2015). 10.1063/1.4930979

S. Heo, D. Kim, and C. Cheong, "Broadband noise prediction of the ice-maker centrifugal fan in a refrigerator using hybrid CAA method and FRPM technique" (in Korean), J. Acoust. Soc. Kr. 31, 391-398 (2012). 10.7776/ASK.2012.31.6.391

S. Heo, D. Kim, C. Cheong, and T.-H. Kim, "Prediction of intenal broadband noise of a centrifugal fan using stochastic turbulent synthetic model" (in Korean), Trans. Korean Soc. Noise Vib. Eng. 21, 1138-1145 (2011). 10.5050/KSNVE.2011.21.12.1138

S. Heo, C. Cheong, and T.-H. Kim, "Development of low-noise centrifugal fans for a refrigerator using inclined S-shaped trailing edge," Int. J. Refrigeration, 34, 2076-2091 (2011). 10.1016/j.ijrefrig.2011.07.003

S. Heo, D. Kim, and C. Cheong, "Analysis of relative contributions of tonal noise sources in volute tongue region of a centrifugal fan" (in Korean), J. Acoust. Soc. Kr. 33, 40-47 (2014). 10.7776/ASK.2014.33.1.040

D. Shin, S. Heo, C. Cheong, T.-H. Kim, and J. Jung, "Performance/noise optimization of centrifugal fan using response surface method," Trans. KSME-A, 41, 165-172 (2017).

D. Shin, S. Y. Ryu, C. Cheong, T. H. Kim, and J. Jung, "Development of high-performance/low-noise centrifugal fan circulating cold air inside a household refrigerator by reduction of vortex flow" (in Korean), Trans. Korean Soc. Noise Vib. Eng. 26, 428-435 (2016). 10.5050/KSNVE.2016.26.4.428

J. Choi, S. Y. Ryu, C. Cheong, M. K. Kim, and K. Lee, "Blade shape optimization of centrifugal fan for improving performance and reducing aerodynamic noise of clothes dryer" (in Korean), J. Acoust. Soc. Kr. 38, 321-327 (2019).

J. Kim, S.-Y. Ryu, C. Cheong, D. Jang, and M. An, "Development of high performance and low noise compact centrifugal fan for cooling automotive seats" (in Korean), J. Acoust. Soc. Kr. 37, 396-403 (2018).

S. Heo, M. Ha, T.- H. Kim, and C. Cheong, "Development of high-performance and low-noise axial-flow fan units in their local operating region," JMST. 29, 3653-3662 (2015). 10.1007/s12206-015-0809-3

G. Ren, S. Heo, T. H. Kim, and C. Cheong, "Response surface method-based optimization of the shroud of an axial cooling fan for high performance and low noise," JMST. 27, 33-42 (2013). 10.1007/s12206-012-1220-y

S. Y. Ryu, S. Kim, C. Cheong, S. M. Park, J. W. Kim, and B. I. Park, "Optimization of flow performance by designing orifice shape of outdoor unit of air-conditioner" (in Korean), J. Acoust. Soc. Kr. 36, 371-377 (2017).

S. M. Park, S. Y. Ryu, C. Cheong, J. W. Kim, B. I. Park, Y. C. Ahn, and S. K. Oh, "Optimization of the orifice shape of cooling fan units for high flow rate and low-level noise in outdoor air conditioning units," Applied Sciences, 9, 5207 (2019). 10.3390/app9235207

K. Kim, S.-Y. Ryu, C. Cheong, S. Seo, and C. Jang, "Optimal design of impeller in fan motor unit of cordless vacuum cleaner for improving flow performance and reducing aerodynamic noise" (in Korean), J. Acoust. Soc. Kr. 39, 379-389 (2020).

B. J. Lee, D. H. Kim, and J. T. Chung, "Numerical study on effects of splitter chord length and pitchwise location on the flow characteristics in a transonic centrifugal compressor" (in Korean), The KSFM Journal of Fluid Machinery, 19, 5-11 (2016). 10.5293/kfma.2016.19.5.005

O. F. Atac, J. E. Yun, and T. Noh, "Aerodynamic design optimization of a micro radial compressor of a turbocharger," Energies, 11, 1827 (2018). 10.3390/en11071827

L. H. Jawad, S. Abdullah, R. Zulkifli, and W. M. F. W. Mahmood, "Numerical investigation on the effect of impeller trimming on the performance of a modified compressor," CFD Letters, 5, 174-184 (2013).

K. Davood and R. T. Mohammad, "The optimum position of impeller splitter blades of a centrifugal pump equipped with vaned diffuser," FME Transactions, 46, 205-210 (2018). 10.5937/fmet1802205K

G. Taguchi, "Quality engineering (Taguchi methods) for the development of electronic circuit technology," IEEE Transactions on Reliability, 44, 225-229 (1995). 10.1109/24.387375

J. K. Kim, "Experimental study on the optimum design of the flow-path system for a low noise indoor package air-conditioner" (in Korean), J. Mechanical Science and Technology, 28, 1277-1283 (2014). 10.1007/s12206-014-0117-3

Information

Publisher :The Acoustical Society of Korea
Publisher(Ko) :한국음향학회
Journal Title :The Journal of the Acoustical Society of Korea
Journal Title(Ko) :한국음향학회지
Volume : 39
No :6
Pages :524-532
Received Date : 2020-10-07
Accepted Date : 2020-11-12
DOI :https://doi.org/10.7776/ASK.2020.39.6.524

The Journal of the Acoustical Society of KoreaISSN:1225-4428(Print) 2287-3775(Online)한국음향학회

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