You are here
HEAT TRANSFER IN MULTILAYER ENERGETIC NANOFILM ON COMPOSITES SUBSTRATE
 Date Issued:
 2007
 Abstract/Description:
 The main purpose of this work is the physical understanding and the numerical description of the reaction of the dense metastable intermolecular composition (MIC). Energy density of MIC is much higher than conventional energetic material; therefore, MIC finds more applications in the propellant and explosive system. The physical model includes the speed of propagation and rate of reaction, and the relationship between the layer thickness, heat rate, and length of the flame based on physical model. In Part I of this thesis, a onedimensional model based on Weihs was developed for 20 pairs of a multilayer of aluminum and copper oxide. This problem was solved using an assumed value of constant atomic diffusion in Arrhenius' equation to obtain the velocity of self propagation. Using the maximum and minimum measured velocities in a similar configuration, the activation energy was computed and was found to be significantly different. When the velocity was used to obtain a linear temperature profile, the margin of error was significant as well. Therefore, this method was seen to have severe shortcomings. In Part II of this thesis, adiabatic unit cell of one layer of aluminum and copper oxide in an ideal reaction was considered. Temperature profile based on chemical heat generation and phase transformation of reactants has been calculated. This model confirmed the highest possible temperature during reaction of 2920 C ± 5% obtained in the literature, however, the model was unable to provide other important flame characteristics. In Part III, a twodimensional model was developed introducing the flame at the interface. A black box theory has been used to simplify some of the characteristics of the flame, ignoring diffusion characteristics. Using this model, the length of flame was calculated using the measured value of the speed of propagation of the flame. Measuring some of the characteristics of the flame was the main goal of Part III of this thesis. Controllable environment was created for the multilayer thin film of aluminum and copper oxide to eliminate the number of effective variables that affect the speed of propagation. Transformable heat of reaction was used to control the speed of propagation. In addition, a MIC sample was designed and fabricated to measure the speed of propagation with an accuracy of 0.1 m/s. This measurement technique was used to measure the speed of propagation on variable substrate up to 65 m/s. The flame length was also calculated for different speeds of propagation over different substrates. The temperature distribution on the substrate was calculated numerically. Significant improvements have been made in Part III; however, this model does not provide concentration profiles. For future work, a more complete twodimensional physical model will be developed for selfpropagation reaction of multilayer thin film of aluminum and copper oxide based on thermal transport and atomic diffusion. This twodimensional model includes the reaction rate, speed of propagation and the temperature profile. Since this model relies on a number of physical variables that are as yet unknown, further work is warranted in this area to carry out a thorough computational study.
Title:  HEAT TRANSFER IN MULTILAYER ENERGETIC NANOFILM ON COMPOSITES SUBSTRATE. 
18 views
7 downloads 

Name(s): 
amini manesh, navid, Author Kumar , Ranganathan , Committee Chair University of Central Florida, Degree Grantor 

Type of Resource:  text  
Date Issued:  2007  
Publisher:  University of Central Florida  
Language(s):  English  
Abstract/Description:  The main purpose of this work is the physical understanding and the numerical description of the reaction of the dense metastable intermolecular composition (MIC). Energy density of MIC is much higher than conventional energetic material; therefore, MIC finds more applications in the propellant and explosive system. The physical model includes the speed of propagation and rate of reaction, and the relationship between the layer thickness, heat rate, and length of the flame based on physical model. In Part I of this thesis, a onedimensional model based on Weihs was developed for 20 pairs of a multilayer of aluminum and copper oxide. This problem was solved using an assumed value of constant atomic diffusion in Arrhenius' equation to obtain the velocity of self propagation. Using the maximum and minimum measured velocities in a similar configuration, the activation energy was computed and was found to be significantly different. When the velocity was used to obtain a linear temperature profile, the margin of error was significant as well. Therefore, this method was seen to have severe shortcomings. In Part II of this thesis, adiabatic unit cell of one layer of aluminum and copper oxide in an ideal reaction was considered. Temperature profile based on chemical heat generation and phase transformation of reactants has been calculated. This model confirmed the highest possible temperature during reaction of 2920 C ± 5% obtained in the literature, however, the model was unable to provide other important flame characteristics. In Part III, a twodimensional model was developed introducing the flame at the interface. A black box theory has been used to simplify some of the characteristics of the flame, ignoring diffusion characteristics. Using this model, the length of flame was calculated using the measured value of the speed of propagation of the flame. Measuring some of the characteristics of the flame was the main goal of Part III of this thesis. Controllable environment was created for the multilayer thin film of aluminum and copper oxide to eliminate the number of effective variables that affect the speed of propagation. Transformable heat of reaction was used to control the speed of propagation. In addition, a MIC sample was designed and fabricated to measure the speed of propagation with an accuracy of 0.1 m/s. This measurement technique was used to measure the speed of propagation on variable substrate up to 65 m/s. The flame length was also calculated for different speeds of propagation over different substrates. The temperature distribution on the substrate was calculated numerically. Significant improvements have been made in Part III; however, this model does not provide concentration profiles. For future work, a more complete twodimensional physical model will be developed for selfpropagation reaction of multilayer thin film of aluminum and copper oxide based on thermal transport and atomic diffusion. This twodimensional model includes the reaction rate, speed of propagation and the temperature profile. Since this model relies on a number of physical variables that are as yet unknown, further work is warranted in this area to carry out a thorough computational study.  
Identifier:  CFE0001775 (IID), ucf:47265 (fedora)  
Note(s): 
20070801 M.S. Engineering and Computer Science, Department of Mechanical Materials and Aerospace Engineering Masters This record was generated from author submitted information. 

Subject(s):  Thin Film  
Persistent Link to This Record:  http://purl.flvc.org/ucf/fd/CFE0001775  
Restrictions on Access:  campus 20080701  
Host Institution:  UCF 