Parametric Sizing of Composite Metal Lined Tanks for Bimodal Nuclear Thermal Propulsion Applications

• Main Authors: Abumeri, Galib H, Roche, Joseph M
• Format: Conference Proceeding
• Language: English
• ISSN: 0094-243X
• DOI: 10.1063/1.2169263

A computational method is described to evaluate the structural performance of composite over-wrapped metal lined LH2 tanks. This work was performed in support of the human space exploration initiative undertaken by NASA. The method is a judicious combination of available computer codes for finite elements, composite mechanics, durability, damage tracking, and damage tolerance. To illustrate the effectiveness of the analytical approach, composite over-wrapped LH2 core tanks of the Bimodal Nuclear Thermal Rocket (BNTR) were sized parametrically using launch loads and burst test requirements. The benefits and debits of inserting advanced composite technology into existing LH2 tank design concepts are evaluated in the paper. Results obtained indicate that LH2 tanks made from tape placement carbon fiber in a toughened epoxy matrix backed by a metallic liner for hermiticity are able to: (1) sustain micro-cracking in the matrix of the composite system prior to liner failure, (2) offer significant weight savings as compared to present technology (up to 31%), and (3) use unified design and weight configuration to support both launch loads and burst test requirements. The structural performance and sizing evaluation was performed for composite tanks varying in length from 10 m to 28 m. Weight calculations for the composite over-wrapped tanks show that the larger the tank length, the larger the weight savings (compared to those of traditional metallic tanks).