Building a Software for Prediction of Noise Propagation in a Complex Condition (Indoor to Outdoor)

Abstract

The aim of this study was to design and build a software for noise propagation prediction (indoor and from indoor to outdoor spaces) being commonly used in industry. In this regard, firstly a mathematical complex model was created based on existing relationships on noise propagation in indoor spaces and transmission through the walls and propagation in outdoor spaces. To model noise propagation from indoor to outdoor, the function of this model is based on meshing the wall which is effective on outdoor receiver point. By analyzing the required inputs and outputs and designing and documenting the process algorithm, the mathematical model was created and the software was built. In the process of meshing the wall, the software divides the effective wall into 20 parts in length and width and calculations related to sound pressure level on inner wall surface, transmission loss through the wall and leakage from the pores are performed on these meshes. The built software was designed in five forms. Form one for defining hall dimensions and areas of used materials, form two and tree for defining sound sources inside the hall and form five for defining and managing materials were designed. Form four was used for completing required information and monitoring calculation results and software outputs. The software was run with the input data of a gas power plant and outputs were analyzed. The average relative difference between outputs of software (sound pressure levels in given points) and field measurements was below 5%.