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Two Phase Flow Phase Change and Numerical Modeling Part 2

Tham khảo tài liệu 'two phase flow phase change and numerical modeling part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 20 Two Phase Flow Phase Change and Numerical Modeling Input data Pl - laser power f - focal distance of the focusing system ton - laser pulse duration tp - laser pulse period p - additional gas pressure g - material thickness n -number of time steps that program are running for t - time step M N - number of digitization network in Ox and Oy directions respectively. Both procedures the main function and the procedure computing the boundaries were implemented as MathCAD functions. 4. Numeric results The model equations were solved for a cutting process of metals with a high concentration of iron steel case . In table 1 is presented the temperature distribution in material computed in continuous regime lasers with the following input data PL lkw laser power O 0.74 oxidizing efficiency p 0.8bar additional gas pressure d 0.16mm focalized laser beam radius D 10mm diameter of the generated laser beam f 145mm focal distance of the focusing system g 6mm material thickness As 0.49 absorbability on solid surface AL 0.68 absorbability on liquid surface t 105s time step t 10ms operation time M 8 number of intervals on X direction N 32 number of intervals on y direction kT 1000 number of iterations . The iron material constants were taken into consideration accordingly to the present solid liquid or vapor state. The real temperatures in material are the below ones multiplied by 25. Temperature distribution was represented in two situations at the material surface and at the material evaporating depth z 4.192mm figure 3 . T K 3000- b z 4.192 mtn Fig. 3. Temperature distribution PL lkw t 10ms The depths corresponding to the melting and vaporization temperatures are ztop 4.288mm respectively zvap 4.192mm. The moments when material surface reaches the vaporization and melting temperatures are t 0.181 10 5S respectively tt 0.132 10 5S . The temperature distributions at different depths within the material for laser power PL 400W and processing time t 1ms are presented in figure 4. .