Accession Number : ADA259519


Title :   X-Ray Computed Tomography for Whole System Evaluation (Small Engines)


Descriptive Note : Interim rept. Jun 1990-Feb 1991


Corporate Author : BOEING DEFENSE AND SPACE GROUP SEATTLE WA


Personal Author(s) : Crews, Alan R ; Bossi, Richard H


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a259519.pdf


Report Date : 31 May 1992


Pagination or Media Count : 52


Abstract : Under a preliminary testing task assignment of the Advanced Development of X-Ray Computed Tomography Application program, computed tomography (CT) has been studied for its potential as an engineering analysis tool and an in-service nondestructive evaluation method for whole systems such as small jet engines. CT evaluation has been employed on small jet engines demonstrating its viability for assembly verification, dimensional profiles, and foreign object detection without disassembly. CT systems with energies of 400 KV, 2 MV, 2.5 MV and 9 MV were used in the study. The sensitivity to feature details in complex systems, such as the jet engines, is improved with higher signal to noise for the same inherent resolution. For long metal paths, the highest energy available is preferred, however many of the 2 MV images showed good sensitivity to internal details, and even 400 kV can be usefully employed in some regions of an engine. The quantitative capability of CT to measure the relative X-ray linear attenuation coefficient and position of small volume elements in an object offers the potential to directly calculate the center-of- gravity (CG) of the object from the CT scan data. Results of CT tests on a test phantom indicates that under certain conditions CG calculations can be made for CT data with sensitivity on the order of O.15 g-cm in aluminum at 3 cm radius... . Density, Computed Tomography (CT), Jet engine, Air Launched Cruise Missile (ALCM), Foreign object detection, Center-of-Gravity (CG), Nondestructive Eval/Inspection(NDE/1).


Descriptors :   *JET ENGINES , *X RAYS , *TOMOGRAPHY , TEST AND EVALUATION , METALS , DENSITY , VOLUME , CENTER OF GRAVITY , DETECTION , FOREIGN , SENSITIVITY , IMAGES , SIGNALS , CRUISE MISSILES , COEFFICIENTS , ALUMINUM , INTERNAL , ENGINEERING , PROFILES , REGIONS , DISASSEMBLY , AIR LAUNCHED , ASSEMBLY , NOISE , GRAVITY , PHOSGENE , ATTENUATION , ALLOCATIONS , ENGINES , VIABILITY , VERIFICATION , TOOLS , MATERIALS , ENERGY , RESOLUTION , SHAPE , PATHS


Subject Categories : Nuclear Physics & Elementary Particle Physics
      Jet and Gas Turbine Engines


Distribution Statement : APPROVED FOR PUBLIC RELEASE