equations is considered here. A numerical convergence check and a comparison with a. finite element treatment of a companion geometry provide confidence in the results found which focus on the key quantity in linear elastic fracture mechanics (LEFM), the energy release rate, G. The effect of the free surface/crack intersection in the basic configuration considered here is found to be small in the context, of LEFM. This effect is found to be greater in configurations containing presumed compressive near-surface residual stresses, indicating possible merit in their further investigation. (Dissert. Abstr.) Source of Abstract (Subfile): Dissert. Abstr. Descriptors: *FINITE ELEMENT METHOD; *FRACTURE MECHANICS; *INTEGRAL EQUATIONS; *LINEARITY; *TENSILE STRESS; CRACK PROPAGATION; ENERGY DISSIPATION; RESIDUAL STRESS Subject Classification: 7539 Structural Mechanics (1975-) Solar photochemical process engineering for production of fuels and chemicals. BIDDLE, J. R.; PETERSON, D. B. ; FUJITA, T. (JPL) California State Polytechnic Univ., Pomona. Corp. Source Code: CC291532 May 1984. 93P. Publication Note: Prepared for JPL. Report No.: NASA-CR-173910; DOE/JPL-1060/72; JPLPUB-84-31 ; NAS 1.26:173910; REPT-5105-130 Contract No.: NAS7-918; DE-AM04-80AL-13137 Language: English. Country of Origin: United States. Country of Publication: United S t a t es Document Typ e: REPORT Most, documents available from AIAA Technical Library Other Availability: NTIS HC A05/MF. AOI Journal Announcement: SIA R B 4 2 2 The engineering costs and performance of a nominal 25,000 scmd (883,000 scf d) ph ot oc hemi ca1 p1 an t t o prod uc e di hydrogen from water were studied. Two systems were considered, one based on flat-plate col 1ector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the col 1ector/reactor, support hardware, field transport piping, gas compression equipment, and b a1 an ce-of-p1 an t (BOP) items. Overall plant efficiencies of 10.3 and 11.67. are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.67.. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non- concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. The overall plant efficiency is the single most important factor in determining the cost of the fuel. (Author) Descriptors: *CHEMICAL ENGINEERING; *PHOTDCHEMICAL
RkJQdWJsaXNoZXIy MTU5NjU0Mg==