Engineering topics

Malroy, Eric T.

Publications and source records attributed to Malroy, Eric T..

3 records

NASA NTRS2010

Feasibility Study of Interstellar Missions Using Laser Sail Probes Ranging in Size from the Nano to the Macro

This paper presents the analysis examining the feasibility of interstellar travel using laser sail probes ranging in size from the nano to the macro. The relativistic differential equations of motion for a laser sail are set up and solved using the Pasic Method. The limitations of the analysis are presented and discussed. The requirements for the laser system are examined, including the thermal analysis of the laser sails. Black holes, plasma fields, atmospheric collisions and sun light are several methods discussed to enable the deceleration of the interstellar probe. A number of novel mission scenarios are presented including the embryonic transport of plant life as a precursor to the arrival of space colonies

Malroy, Eric T.↗

NASA NTRS2008

External Tank (ET) Foam Thermal/Structural Analysis Project

An independent study was performed to assess the pre-launch thermally induced stresses in the Space Shuttle External Tank Bipod closeout and Ice/Frost ramps (IFRs). Finite element models with various levels of detail were built that included the three types of foam (BX-265, NCFI 24-124, and PDL 1034) and the underlying structure and bracketry. Temperature profiles generated by the thermal analyses were input to the structural models to calculate the stress levels. An area of high stress in the Bipod closeout was found along the aluminum tank wall near the phenolic insulator and along the phenolic insulator itself. This area of high stress might be prone to cracking and possible delamination. There is a small region of slightly increased stress in the NCFI 24-124 foam near its joint with the Bipod closeout BX-265 foam. The calculated stresses in the NCFI 24-124 acreage foam are highest at the NCFI 24-124/PDL 1034/tank wall interface under the LO2 and LH2 IFRs. The highest calculated stresses in the LH2 NCFI 24-124 foam are higher than in similar locations in the LO2 IFR. This finding is consistent with the dissection results of IFRs on ET-120.

Moore, David F.↗

NASA NTRS2007

Free Molecular Heat Transfer Programs for Setup and Dynamic Updating the Conductors in Thermal Desktop

The programs, arrays and logic structure were developed to enable the dynamic update of conductors in thermal desktop. The MatLab program FMHTPRE.m processes the Thermal Desktop conductors and sets up the arrays. The user needs to manually copy portions of the output to different input regions in Thermal Desktop. Also, Fortran subroutines are provided that perform the actual updates to the conductors. The subroutines are setup for helium gas, but the equations can be modified for other gases. The maximum number of free molecular conductors allowed is 10,000 for a given radiation task. Additional radiation tasks for FMHT can be generated to account for more conductors. Modifications to the Fortran subroutines may be warranted, when the mode of heat transfer is in the mixed or continuum mode. The FMHT Thermal Desktop model should be activated by using the "Case Set Manager" once the model is setup. Careful setup of the model is needed to avoid excessive solve times.

Malroy, Eric T.↗