Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Attach”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 649 records · Page 36
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

On the interaction between the shock wave attached to a wedge and freestream disturbances

A study of the interaction of small amplitude, unsteady, freestream disturbances with a shock wave induced by a wedge in supersonic flow is presented. These disturbances may be acoustic waves, vorticity waves, or entropy waves (or indeed a combination of all three). Their interactions then generate behind the shock disturbances of all three classes, an aspect that is investigated in some detail, our motivation being to investigate possible mechanisms for boundary-layer receptivity, caused through the amplification and modification of freestream turbulence through the shock-body coupling. Also, the possibility of enhanced mixing owing to additional vorticity produced by the shock-body coupling is investigated.

Duck, Peter W.↗
NASA NTRS1994

Attachment device

An apparatus is disclosed for capturing and holding a rod, bar or similar member; the apparatus having in one aspect a body member with a recess therein and a hook extending from the body member, the hook and recess defining a capture envelope for receiving and confining the rod, etc. In one aspect such an apparatus is disclosed in which the hook is movable with respect to the body member to vary the size of the capture envelope, both to initially facilitate emplacement of the apparatus about the rod, etc., and then to provide for tightening of the apparatus about the rod, etc., if desired.

Zaguli, Ronald J.↗
NASA NTRS1997

Contact Sensor Attachment to Titanium Metal Composites

A Pd-13wt%Cr solid solution is a promising high-temperature strain gage alloy. In bulk form it has a number of properties that are desirable in a resistance strain gage material, such as a linear electrical-resistance-versus-temperature curve to 1000 C and stable electrical resistance in air at 1000 C. However, unprotected fine wire gages fabricated from this alloy perform well only to 600 C. At higher temperatures severe oxidation degrades their electrical performance. In this work Auger electron spectroscopy has been used to study the oxidation chemistry of the alloy wires and ribbons. Results indicate that the oxidation is caused by a complex mechanism that is not yet fully understood. As expected, during oxidation, a layer of chromium oxide is formed. This layer, however, forms beneath a layer of metallic palladium. The results of this study have increased the understanding of the oxidation mechanism of Pd-13wt%Cr.

Vargas-Aburto, Carlos↗
NASA NTRS2001

Roughness-Dominated Transition on Nosetips, Attachment Lines and Lifting-Entry Vehicles

Modeling of roughness-dominated transition is a critical design issue for both ablating and non-ablating thermal protection systems (TPS). Ablating TPS, used for planetary-entry and earth-return missions, first experience recession under high-altitude, low-Reynolds-number conditions. Such laminar-flow ablation causes the formation of a surface microroughness pattern characteristic of the TPS material composition and fabrication process. For non-ablating TPS, such as the overlapping-tile, metallic heatshields proposed for future reusable launch vehicles, the surface roughness pattern is established a priori by the engineering design and assembly procedure. In both cases, these distributed surface roughness patterns create disturbances within, and alter the mean velocity profile of, the laminar boundary layer flowing over the surface. As altitude decreases, Reynolds number increases, and flow field conditions capable of amplifying these roughness-induced perturbations are eventually achieved, i.e., transition onset occurs. Boundary layer transition to turbulence results in more severe heat-transfer rates. Ablating TPS experience increased recession rates, leading to potential bum-through, while non-ablating TPS experience accelerated temperature rise, leading to potential melting of key components.

Reda, Daniel C.↗
NASA NTRS2002

Attachment Fitting for Pressure Vessel

This invention provides sealed access to the interior of a pressure vessel and consists of a tube. a collar, redundant seals, and a port. The port allows the seals to be pressurized and seated before the pressure vessel becomes pressurized.

Stanley S Smeltzer, III↗
NASA NTRS2003

Simulation of the Flow Field Associated with a Rocket Thruster Having an Attached Panel

Two-dimensional inviscid and viscous numerical simulations are performed to predict the flow field induced by a H2-O2 rocket thruster and to provide insight into the heat load on the articles placed in the hot gas exhaust of the thruster under a variety of operating conditions, using the National Combustion Code (NCC). The simulations have captured physical details of the flow field, such as the plume formation and expansion, formation of the shock waves and their effects on the temperature and pressure distributions on the walls of the apparatus and the flat panel. Comparison between the computed results for 2-D and adiabatic walls and the related experimental measurements for 3-D and cooled walls shows that the results of the simulations are consistent with those obtained from the related rig tests.

Davoudzadeh, Farhad↗
NASA NTRS2003

See Attachment

Since e-mail generates itself on a round-the-clock, daily basis, it's not unusual for me to receive an average of fifty e-mails a day, or more than 300 a week. That s a lot of e-mail. I have spoken with many of my fellow project managers about my relationship with e-mail. In my case, reading and responding to it is a temptation almost too hard to resist. When I receive an e-mail I tend to want to stop everything I m doing, and open and answer it. Indeed, in my life you could say e-mail is a force to be reckoned with. Interestingly, my fascination with mail began a long time ago. I trace it back to my days as a young boy when I started receiving my first letters from friends and family. Walking home from school, I was often filled with curiosity, wondering if I had received any mail that day. In college, I knew the exact time the mail was delivered, and I headed for my mailbox as close to that hour as I could. After that, I served in an Army Reserve Post Office Unit, where I came to realize how important a postal unit was to the military. There were many others like myself, far from home, who relied on the written word to stay connected to the people in their lives. Over the years I have changed in many ways, and so has the mail. But the same sense of connection, and the same urge to respond to someone who has written me, remains. The 24/7 nature of e-mail has compounded the situation. It is relentless in its pursuit of my time and attention-and, as such, e-mail has become something I have had to manage in a variety of situations

Cameron, W. Scott↗