Bolton, J Stuart

Hong, Kwanwoo

Yum, Kiho

English

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Purdue UniversityPurdue e-PubsPublications of the Ray W. Herrick Laboratories School of Mechanical Engineering12-2006Experimental Relationship Between Tire'sStructural Wave Propagation and Sound RadiationJ Stuart BoltonPurdue University, bolton@purdue.eduKwanwoo HongKiho YumHyundai Motor CompanyFollow this and additional works at: http://docs.lib.purdue.edu/herrickThis document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact epubs@purdue.edu foradditional information.Bolton, J Stuart; Hong, Kwanwoo; and Yum, Kiho, "Experimental Relationship Between Tire's Structural Wave Propagation andSound Radiation" (2006). Publications of the Ray W. Herrick Laboratories. Paper 38.http://docs.lib.purdue.edu/herrick/38INTER-NOISE 20063-6 DECEMBER 2006HONOLULU, HAWAII, USAExperimental relationship  between tire’s structural wave propagation and sound radiation  Kiho Yum Kwanwoo Hong and J Stuart Bolton               .  Hyundai Motor Co                    Ray W. Herrick LaboratoriesMechanical EngineeringPurdue universityTire Noise■ Significance of Tire Noise[ SPL inside Passenger Cabin ]Vibration Mode (Structure-borne)Cavity NoiseVibration☞ Structure-borne☞ Air-bornePattern  (Whine)Air Pumping  (Sizzle)Horn Effectp2Objectives and Contents■ Objectives• To identify structural wave propagation on tire surface and its sound radiation experimentally ■ Contents • Structural vibration on tire surface – Experimental structural mobility distribution on tire surface– Structural wave propagation characteristics on tire surface• Sound radiation from a tire– Sound radiation measurement and calculation– Radiated sound power characteristics• Relationship between structural wave propagation characteristics and its sound radiationp3Structural Vibration Measurement■ Structural vibration measurement on tire surface– Normal harmonic force was applied on the treadband center point of      the slick tire (205/70R14 Tire).– Structural mobility was measured on whole tire surface. (except on wheel) p4Structural Vibration Measurement■ Structural velocity (mobility) distributiontreadbandsidewallsidewallm=3 m=7p5Structural Wave Propagation■ Circumferential Wave Number Decompositionstructural velocity distribution structural velocity distribution in space domainfl l longitudinal in wave number domainexura  wave wave ring mode(ring frequency)cut-on freqof flexural m=5m=7wave modem=3m=1treadband center linep6Structural Power Contribution`■ Structural input powercut-on frequency of flexural wave mode20 b bE cS v[ experiment ]• Structural vibrations below 300 Hz,  transferred to the interior cabin, appears mainly on treadband.• Sidewall’s contribution on structural power is higher in the mid-frequency region.p7Sound Radiation Measurement■ Nearfield SPL and intensity measurement and calculation– Nearfield sound radiation resulting from a tire’s structural vibration was measured and calculated.– Sound radiation was measured in the hemi-anechoic chamber.– Radiated sound calculation using D-BEM was based on the structural mobilities obtained in the structural vibration measurement.p8Nearfield Radiation Model■ Nearfield Sound Radiation Model• To validate BE calculation by comparing with measurement results  N fi ld SPL d i t it d d l l t d i f t f• ear e   an  n ens y were measure  an  ca cu a e  n ron  o  treadband centerline.• Nearfield radiated sound power was measured and calculated on half-box recovery surface  .[ nearfield SPL and intensity model ] [ nearfield sound power model ]p9Nearfield Sound Radiation■ Nearfield SPL distributionring frequency• Generally calculation results are matching well with measurement results.[ measurement ] [ calculation ]• SPL at the ring frequency, 570 Hz, is higher all over circumferential positions.  • Region close to contact patch area has high SPL level above 1000 Hz: Horn effect characteristics. p10Nearfield Sound Radiation■ Nearfield intensity distributionGenerally calculation results are matching well with measurement results[ measurement ] [ calculation ]•         .• Flexural motion on treadband contributes to nearfield sound radiation below 400 Hz.  • Intensity at the ring frequency, 570 Hz, is higher all over circumferential locations.p11Sound Radiation from a Tire■ Nearfield intensity distribution at 570 HzFRONT TOPFRONTTOP[ measurement ] [ calculation ]RIGHTLEFT LEFTRIGHT    • Generally calculation results are matching well with measurement results.• Sound radiation from whole tire surface dominates at the ring frequency.p12Structural Vibration/Radiation Relationship■ Relationship between structural wave propagation and its radiation– Radiated power peaks don’t match with those of structural power. – Structural input power peaks appear atcut-on frequencies of flexural wave mode. cut-on frequency of flexural wave mode– Radiated power peaks appear whenstructural wave has low wave number.– The peak at 570 Hz relates to          ‘ring frequency’. – Structural vibration below the ring frequencydoes not contribute to sound radiationring frequency1st & 2nd wave number component of longitudinal wave      effectively.p13Summary and Conclusions• The sound radiation resulting from the structural wave propagation was investigated.• The relationship between structural wave propagation on the tire surface and its radiation was identified empirically.• Most of a tire’s structural vibration does not contribute to sound radiation.• Effective radiation was found at the frequencies where low wave number components of the longitudinal wave appear     • The fast longitudinal wave propagating through the treadband contributes on sound radiation at the tire’s ring frequency.p14Q & A  ~ Thank you ~

Experimental Relationship Between Tire\u27s Structural Wave Propagation and Sound Radiation

https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1038&amp;context=herrick

Experimental Relationship Between Tire\u27s Structural Wave Propagation and Sound Radiation

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