THERMAL EFFECTS OF HIGH ENERGY AND ULTRAFAST LASERS A Thesis Presented to The Faculty of the Graduate School University of Missouri --------------------------------------------------------------------------------------------------------------------- In Partial Fulfillment of the Requirement for the Degree Doctor of Philosophy --------------------------------------------------------------------------------------------------------------------- By Nazia Afrin Thesis Supervisor: Dr. Yuwen Zhang December 2015 DECLARATION The undersigned, appointed by the dean of the Graduate Faculty, have examined the thesis entitled THERMAL EFFECTS OF HIGH ENERGY AND ULTRAFAST LASER Presented by NAZIA AFRIN A candidate for the degree of Doctor of Philosophy in Mechanical and Aerospace Engineering, and hereby certify that, in their opinion, it is worthy of acceptance. Professor Dr. Yuwen Zhang Professor Dr. Jinn-Kuen Chen Professor Dr. Gary Solbrekken Professor Dr. Matt Maschmann Professor Dr. Stephen Montgomery-Smith DEDICATION I dedicate this thesis to my parents, Shamsun Nahar Islam and late F.K.M. Aminul Islam, my husband Zobayer Khizir, my sister Dr. Aneesa Islam Keya for their endless love and support. ACKNOWLEDGEMENT I am highly grateful to my supervisor Professor Dr. Yuwen Zhang, Chairman of Department of Mechanical and Aerospace Engineering for his encouragement, support, patience and guidance throughout this research work also in daily life. This dissertation would not have been possible without guidance and help of him. I would like to thank the members of my thesis evaluation committee, Dr. J. K. Chen, Dr. Gary Solbrekken and Dr. Matt Maschmann and Dr. Stephen Montgomery-Smith for giving the time to provide valuable comments and criticism. Special thanks must be extended to Yijin Mao for his help.I would like to thank my all coworkers at my lab. It is really great time to work with them and I really enjoy their company in our lab. I would like to express my gratitude to my parents, Shamsun Nahar Islam and Late F. K. M Aminul Islam. My mother always gives me inspirations all the time about my study. Even though my father is not alive in this world, however, still I feel his contribution on my every success in my life. I also like to thanks my husband Zobayer Khizir for his support. Support for this work by the U.S. National Science Foundation under grant number CBET- 1066917 and CBET- 133611 are gratefully acknowledged. The authors would like to thank the Test Resource Management Center (TRMC) Test and Evaluation/Science & Technology (T&E/S&T) Program for their support. This work is funded by the T&E/S&T Program through the US Army Program Executive Office for Simulation, Training and Instrumentation’s contract number W900KK-08-C-0002. Support for this work by the Air Force Research Lab under grant number STTR FA9451-12 is gratefully acknowledged. ii TABLE OF CONTENTS ACKNOWLEDGEMENT ………………………………………………………………………ii LIST OF FIGURES………………………………………………………………………………vi LIST OF TABLE………………………………………………………...……………………… x NOMENCLATURE……………………………………………………..…………………..….. xi ABSTRACT…………………………………………………………………………………….xix CHAPTER 1: Introduction ……………………………………………………………...….….. 1 CHAPTER 2 Duel-Phase Lag behavior of a gas-saturated porous-medium heated by a short pulse laser 2.1 Introduction ………………………………………………………………..………………. 4 2.2 Physical model ……………………………………………………………………….……. 7 2.3 Laplace transform solution …………………………………………………….………….. 11 2.4 Results and discussion ……………………………………………………….……………. 13 2.5 Conclusion ………………………………………………………………………………… 23 CHAPTER 3 Inverse estimation of front surface temperature of a locally heated plate with temperature-dependent conductivity via Kirchhoff transformation 3.1 Introduction ……………………………………………………………………..…………. 25 3.2 Mathematical and approximation model ………………………………………..…………. 27 3.3 Laplace transform solution …………………………………………………………..…….. 32 3.4 Simulation results ………………………………………………………….……….……… 34 3.5 Conclusion ………………………………………………………………………….……… 44 CHAPTER 4 Multicomponent gas particle flow and heat/mass transfer induced by a localized laser irradiation on a Urethane-Coated stainless steel substrate 4.1 Introduction ………………………………………………………………………...………. 46 4.2 Physical model ……………………………………………………………………………....48 4.2.1 Continuous phase………..………………………………………………………………...48 iii 4.2.2 Chemical reaction ……………………………………………………………….………...52 4.2.3 Discretized phase …………………………………………………………….………….. 56 4.3 Results and discussion ……………………………………………….……………………. 57 4.4 Conclusion ………………………………………………………………………………… 79 CHAPTER 5 Effects of beam size and laser pulse duration on the laser drilling process 5.1 Introduction ………………………………………………………………………...………. 80 5.2 Analytical model …………………………………………………………………...………. 82 5.2.1 Fluid flow ……………………………………….………………………………..………. 83 5.2.2 Heat transfer………………….………………………………………………..…………..84 5.2.3 Optical consideration ….…………………………………………………..………..……. 85 5.3 Numerical simulation …………………………………………………………….………… 88 5.3.1 Velocity and pressure calculation ……………………….…………………….…………. 88 5.3.2 Temperature calculation (solving energy equation) ………………..………….…………89 5.4 Results and discussion ………………………………………………………..……….…… 90 5.4.1 Effects of beam diameter…………………………………………………………………..93 5.4.2 Effects of laser pulse……………………………………………………………………....97 5.5 Conclusion ………………………………………………………………...……………….102 CHPTER 6 Uncertainty analysis of melting and resolidification of gold film irradiated by nano- to-femtosecond lasers using Stochastic method 6.1 Introduction………………………………………………………………..……………….103 6.2 Physical model……………………………………………………………………………...106 6.3 Stochastic modeling of uncertainty…………………………………………………………110 6.4 Results and discussions……………………………………………………………………..112 6.5 Conclusion……………………………………………………..………………………….. 134 7. CONCLUSION ……………………………………………………………………………...135 iv REFERENCES ………………………………………………………………………….……. 138 VITA……………………………………………………………………………………………153 v LIST OF FIGURES Fig. 2-1 Physical model ………………………………………………………………………….8 Fig. 2-2 Powder temperature (Ts) at the heating surface and the adiabatic surface with J = 5 2 1.25×10 J/m , tp = 100 ns, dp = 15µm (τT = τq =3.9 ns): (a) t/tp < 1 and (b) t/tp > 1 …….….15 5 2 Fig. 2-3 Temperature distribution over the powder layer with J = 1.25×10 J/m , tp = 1 ns, dp = 15 µm (τT = τq = 3.9 ns)……………………………………………………………………………..16 Fig. 2-4 Phase lag times (τT and τq) effects on the powder layer temperature: (a) t/tp < 1 and (b) t/tp > 1………………………………………………………………………………………..…..19 Fig. 2-5 Effects of laser fluence (J) on the temperature of powder layer with tp = 10 ns and dp = 15 µm: (a) t/tp < 1 and (b) t/tp > 1…………………………………………………………….…20 5 2 Fig. 2-6 Effects of porosity (φ) on the temperature of powder layer with J = 1.25×10 J/m , tp = 1 ns, and dp = 15 µm: (a) t/tp < 1 and (b) t/tp > 1………………………………………………..22 5 Fig. 2-7 Effects of pulse width (tp) on the maximum temperature of powder layer (J=1.25×10 J/m2)…………………………………………………………………………………………...…23 Fig. 3-1 Relationship between T and for stainless steel with Tr 318 K………..….35 Fig. 3-2 Schematic diagram of meshing on the back surface ……………………………..….36 Fig. 3-3 Comparison of front surface temperature contours for SS 304: Exact (left), CGM (middle) and DCT/Laplace transformation solution (right)………………………………..….39 Fig. 3-4 Front surface temperature distributions along Y direction at different sensors location at time t=1.55s ………………………………………………………………………………….….40 Fig. 3-5 Comparison of front surface temperature between DCT/Laplace transformation and exact solution along Y direction at different sensors location at time t=1.55s ………………41 vi Fig. 3-6 Comparison of CGM and DCT/Laplace transformation solutions of front surface 19L 19L temperature vs time at three sensor locations (center ( Y Y , Z z ), two off centers ( 40 40 25L 19L 29L 19L Y Y , Z z and (Y Y , Z z )) …………………………………..……….…42 40 40 40 40 Fig. 3-7 Comparison of the RMS values at different time steps for DCT/Laplace (reference temperature (Tr) as all average values of back surface temperatures and average of maximum and minimum front surface temperatures) and CGM method ………………………………….…..44 Figure 4-1 Node moving mechanism ……………………………………………………….….55 Figure 4-2 Illustration of mesh arrangement ………………………………………………….58 Figure 4-3 Maxmum temperatures in the paint vs three different mesh configurations…….…64 Figure 4 Temperature distribution across the middle cross section area of the gaseous domain at the end of simulation …………………………………………………………....66 Figure 4-5 Time history of temperatures at the center of laser heating spot for the six laser powers …………………………………………………………………………..….66 Figure 4-6 Density distributions across the middle cross section area of the gaseous domain at the end of simulation …………………………………………………………..…...68 Figure 4-7 Density variations at the center of the laser irradiation spot with time ……..……69 Figure 4-8 Velocity distributions across the middle cross section area of the gaseous domain at the end of simulation ……………………………………………………………….70 Figure 4-9 State of parcel flow and gaseous phase at different times …………………..……72 Figure 4-10 Time histories of the mass concentration of O2, H2O, CO2, NO2 at the center of laser heating spot …………………………………………………………..…………......75 Figure 4-11 Time histories of paint thickness removal for the six laser powers ……….…….76 Figure 4-12 Parcel and gaseous flow at the end of the simulation ………………………..……77 Figure 4-13 Comparison of paint removal between simulation and experiment ………..…...78 vii Figure 5-1 Schematic diagram of laser drilling process……………………………………......83