Designing of Noise Barrier

Lalit Aggarwal P2009ME1088Gayathri Lakshmi K. P2009ME1062

Designing of Noise Barrier 2

Problem description

• Aim• Experimental• Formulation in MATLAB • Modeling using software

Designing of Noise Barrier 3

Index• Experiment• Formulation in MATLAB – Comparison with experimental results– MATLAB GUI

• Modeling using software OLT– Comparison with experimental results– Analysis using software

Designing of Noise Barrier 4

Experiment on hard ground

Designing of Noise Barrier 5

Designing of Noise Barrier 6

Insertion loss due to a semi-infinite barrier

• LAM Method– Diffraction based model– Based on the path difference– Summing the contribution of each path– Applicable for hard ground, thin and semi-infinite

barrier.

Designing of Noise Barrier 7

Paths considered in LAM Method

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MATLAB GUI

Designing of Noise Barrier 9

Comparison

Designing of Noise Barrier 10

Comparison

Designing of Noise Barrier 11Reference: Olive Lab Tree Terrain

0.5 1 1.5 2 2.5 3 3.5 4 4.50

5

10

15

20

25

30

35

Height Variation

1000 Hz1259 Hz1995 Hz3162 Hz3981 Hz

Barrier height(in m)

Inse

rtion

Loss

(in d

B)

Designing of Noise Barrier 12

Required Thickness• Mass Law TL=20*log(m)+20*log(f/100)-7 m=surface density f= frequency

Reference: http://rwsc2.inforce.dk/sw98684.asp

Designing of Noise Barrier 13

0 500 1000 1500 2000 2500 3000 3500 4000 45000

0.02

0.04

0.06

0.08

0.1

0.12

barrier thickness

barrier thickness

Frequency(in Hz)

barr

ier t

hick

ness

(in m

)Material: GlasswoolFlow resistivity=20000 Pas/m2

Designing of Noise Barrier 14

0 10 20 30 40 50 60

-5

0

5

10

15

20

25

30

Thickness Variation

thickness_3cmthickness_3.5cmthickness_4cmthickness_4.5cm

Receiver distance (in m)

Inse

rtion

Loss

(in d

B)Material: GlasswoolFlow resistivity=20000 Pas/m2

Reference: Olive Lab Tree Terrain

Designing of Noise Barrier 15

Single panel barrier Double panel barrier

Reference: Olive Lab Tree Terrain

Designing of Noise Barrier 16

1 2 3 4 5 6 7 8 9 10 110

5

10

15

20

25

30

35

40

45

Insertion Loss variation in double panel barriers

single paneldouble panel_gap10cmdouble panel_gap20cmdouble panel_gap 30cmdouble panel_gap50cmdouble panel gap 40 cm

Receiver distance(in m)

Inse

rtion

Loss

(in d

B)

Frequency = 1000 Hz

Reference: Olive Lab Tree Terrain

Designing of Noise Barrier 17

1 2 3 4 5 6 7 8 9 10 110

5

10

15

20

25

30

35

40

45

Insertion Loss variation in double panel barriers

single paneldouble panel_gap10cmdouble panel gap 20 cmdouble panel_gap 30cmdouble panel_gap 40 cmdouble panel_gap50cm

Receiver distance (in m)

Inse

rtion

Loss

(in d

B)

Frequency = 2000 Hz

Reference: Olive Lab Tree Terrain

Designing of Noise Barrier 18

1 2 3 4 5 6 7 8 9 10 110

5

10

15

20

25

30

35

Variation in flow-resistivity

2.54 cm glasswool (20000)2.54 cm glasswool (50000)5.1 cm glasswool(20,000)gypsum_4,200,000

distance from barrier(in m)

IL(in

dB)

Reference: Olive Lab Tree Terrain

19

Future Work• Experimental Results of Material Selection and

double panel and comparison• Sysnoise design includes shape variation • Matlab for thick barrier

20

ReferencesResearch Papers• A. Muradali and K. R. Fyfe, A Study of 2D and 3D Barrier Insertion Loss

using Improved Diffraction-based Methods, Applied Acoustics, Vol. 53, No. I-3, pp. 49-15, 1998

• Maekawa, Z., Noise reduction by screens. Applied Acoustics, 1968, 1, 157-173.

• D. C. HOTHERSALL, S. N. CHANDLER-WILDE AND M. N. HAJMIRZAE, EFFICIENCY OF SINGLE NOISE BARRIERS, Journal of Sound and Vibration (1991) 146(2), 303-322

Others: • Report on DESIGN THE NOISE BARRIER FOR THE BAFFLE RANGE by Sahil

Bhagat.• http://en.wikipedia.org/wiki/Noise_barrier