Document Type
Dissertation
Date of Award
12-31-2020
Degree Name
Doctor of Philosophy in Mechanical Engineering - (Ph.D.)
Department
Mechanical and Industrial Engineering
First Advisor
N. Chandra
Second Advisor
Zhiming Ji
Third Advisor
Dibakar Datta
Fourth Advisor
Eon Soo Lee
Fifth Advisor
Max Roman
Abstract
Blast-induced traumatic brain injuries have affected U.S. soldiers deployed for extended periods in the gulf and Afghanistan wars. To identify the biomechanical and biochemical mechanisms of injury, critical in the identification of diagnostic and therapeutic tools, compressed gas-driven shock tubes are used by investigators to study shockwave-animal specimen interactions and its biological consequences. However, shock tubes are designed and operated in a variety of geometry with a range of process parameters, and the quality of shock wave characteristics relevant to field conditions and therefore the study of blast-induced traumatic brain injuries suffered by soldiers is affected by those conditions. Lab-to-lab comparison is restricted by these variations, inhibiting data pooling and impeding progress. Shock waves accurately characterized by a validated numerical model can be effective in identifying the relationship between shock characteristics vis-?-vis specific shock tube.
In this work, a finite element model was developed and validated with data from carefully designed experiments. It was hypothesized that the shock wave characteristics are governed by the energy source, geometry of the tube and specimen location, both along the length and within the section. Using three specific aims, it was identified that a truncated finite element model is appropriate. It was also shown, while the shock wave replicated the field parameters inside the shock tube, the characteristics outside the tube was complex and as affected by vortex tube and jet winds. Therefore, it was determined that this location may not be suitable for replication relevant to the mild TBI problem. It was also determined that shape, size, and location of occlusion increases with the ratio of obstruction to shock tube cross-section.
Recommended Citation
Kahali, Sudeepto, "Blast shock-wave characterization in experimental shock tubes" (2020). Dissertations. 1746.
https://digitalcommons.njit.edu/dissertations/1746
