Transmission Loss of Silica Aerogel Granules

7 Evaluation of TL for AG2 and AG3 via proposed inferential method using 2-microphone impedance tube 

GSA-SDS and GSA-SDS/FMWNT specimens of 100 and 29 mm diameter in varying thicknesses are fabricated via FD method described in the same manner as previously reported (Mahesh and Joshi 2015) comprising of 1.2 and 1.7 mm silica aerogel granule sizes (GSA-AG2 and GSA-AG3) as shown in Table 7.3. 

Type Specimen diameter (mm) Granule size (mm) No of layers Thickness (mm) 

The composition of GSA-SDS specimen is 20 wt% gelatin 80 wt% silica aerogels 0.56 wt% SDS as shown in Fig. 7.7. The composition of GSA-SDS/FMWNT is the same as above with the addition of 0.025 wt%. In addition, other materials were also tested for comparative analysis. In addition, other materials were also tested for comparative analysis. The preparation for the acoustic measurements for GSA-SDS specimens is the same as granules described in the above paragraph. 

The acoustic absorption coefficients and the TL of the GSA-SDS composites under various configurations are shown in Table 7.4. 

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