Jeffrey R. Engel's research while affiliated with TDA Research, Inc and other places
What is this page?
This page lists the scientific contributions of an author, who either does not have a ResearchGate profile, or has not yet added these contributions to their profile.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
It was automatically created by ResearchGate to create a record of this author's body of work. We create such pages to advance our goal of creating and maintaining the most comprehensive scientific repository possible. In doing so, we process publicly available (personal) data relating to the author as a member of the scientific community.
If you're a ResearchGate member, you can follow this page to keep up with this author's work.
If you are this author, and you don't want us to display this page anymore, please let us know.
Publications (19)
: The internal surfaces of liquid hydrocarbon-fueled rocket engine thrust chambers, throats, and nozzles are exposed to high pressure combustion products at temperatures beyond 6000 F. Regenerative cooling is widely used in these engines to prevent overheating of the copper alloy liners. As a result, high heat flux fuel-wetted surfaces reach temper...
The effective control and safening of solid wastes presents a challenge for long-term space missions. A six-month mission will generate over 300 kg of solid wastes per crewmember that must be dealt with to avoid needing room for storage or posing a biological hazard to the crew. Thus, several methods have been explored that include rapid ozone oxid...
This paper reports the synthesis, characterization, and performance of steam-reforming catalysts based upon dispersed Rh particles on Sr-substituted hexaaluminate supports. As confirmed by electron microscopy and X-ray diffraction, the Sr-substituted hexaaluminate provides a plate-like support structure that resists sintering and occlusion of the R...
TDA Research Inc has identified several additives that block the formation of the metastable carbide intermediates on high alloy metal surfaces during the thermal cracking of n-heptane. Laboratory experiments were conducted to measure the effect of the Se additive on reducing filamentous coke formation in metal tubes. Inconel 625 and Incoloy 800HT...
In February 2004 NASA released "The Vision for Space Exploration." The goals outlined in this document include extending the human presence in the solar system, culminating in the exploration of Mars. A key requirement for this effort is to identify a safe and effective method to process waste. Methods currently under consideration include incinera...
Hexaaluminate catalysts offer excellent high-temperature stability compared to the equivalent metal-based catalysts. Their stability also lends well to use as a catalyst support. However, use of novel hexaaluminates is limited in fuel processing for fuel-cell applications. In this paper, we report on the performance of hexaaluminates as a catalyst...
Hypersonic air-breathing vehicles travel at high speeds and generate heat loads that are greater than can be met from sensible heating of the fuel. However, the fuel can provide about 50% more heat sink capacity if it undergoes endothermic thermal cracking reactions before combustion. Unfortunately, thermal cracking reactions require high temperatu...
This paper reports the results of experimental and modeling efforts to characterize partial oxidation of methane to produce synthesis gas (H2 and CO) using metal-substituted hexaaluminate catalysts in short-contact-time reactors. Hexaaluminate catalysts offer excellent high-temperature stability compared to the equivalent metal-based catalysts. The...
Currently, there is a strong need to develop new weapons systems that incorporate advanced propulsion technologies. However,
these systems place severe demands on combustion and thus methods to improve combustion by reducing ignition delay or widening
the stable flame conditions are also required. Although a catalyst would allow combustion to begin...
In this paper we have carried out numerical calculations and electrospray experiments to understand the underlying physics of colloid thruster operation and support the design of micro fabricated colloid thruster arrays. The calculations show that the Hagen-Poiseuille analytic solution predicts the steady flow behavior of the pressure feed system w...
The cost of delivering the payloads to space increases dramatically with distance and therefore missions to deep space place a strong emphasis on reducing launch weight and eliminating resupply requirements. The Vapor Phase Catalytic Ammonia Removal (VPCAR) system, which is being developed for water purification, is an example of this focus because...
Recently, NASA has increased its emphasis on reducing the cost of reaching low Earth orbit. Studies indicate that using a rocket based combined cycle (RBCC) engine could help achieve significant cost reductions. In the third stage of a RBCC launch, the air-breathing vehicle will travel at speeds from Mach 5 to Mach 10 prior to exiting the atmospher...
Hexaaluminate catalysts offer excellent high-temperature stability compared to the equivalent metal-based catalysts. Their stability also lends well to use as a catalyst support. How-ever, use of novel hexaaluminates is limited in fuel processing for fuel-cell applications. In this paper, we report on the per-formance of hexaaluminates as a catalys...
Citations
... Corporation [20]. TDA recently developed a low temperature waste oxidation system [21]. A Heat Melt Compactor for stabilizing plastics and related wastes has been under active development by NASA with promising results [2][3][4][5][6]. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/447196354093058-1483631327796_Q64/James-Nabity-2.jpg)
... In recent decades, active scientific research has been carried out on the creation of promising air regeneration systems for pressurized habitable objects (PHOs), while chemical air regeneration systems based on potassium superoxide are most widely used in Russia and abroad [1][2][3][4][5][6][7][8][9][10][11][12]. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/500485158780928-1496336368894_Q64/Scott-Cowley.jpg)
... The product gases are similar to those produced by incineration, with complete conversion to carbon dioxide and water, and trace amounts of carbon monoxide. The ozone oxidation system was developed by TDA Research, Inc. (Wheat Ridge, CO), under a Small Business Innovation Research (SBIR) grant monitored at Ames Research Center (ARC) 4,5 . It operates by feeding oxygen to an ozone generator, which converts 5% of the oxygen to ozone. ...
... 70 At 600°C and 35 bar pressure, the heptane conversion increased by about 1.7 times (from 7.5 to 12.5%) in the presence of 5.5 wt % triethylamine. Wickham et al. 72,73 have examined the effect of diphenyl selenide (DPS) on the endothermic heat sink capacity of various fuels, namely, n-heptane, JP-7, n-decane, and Norpar-12. The addition of 4 wt % DPS enhanced the total heat sink capacity of n-heptane to a tune of around 17.5% and feed conversion from 5.4% to 32% at 570°C and 38 bar pressure. ...
... In agreement with the results of earlier studies [23,39] the addition of DMDS does not reduce the amount of cokes deposited in the reactor coil. Addition of very small amounts of DMDS (5-20 ppm DMDS) can result in a decrease of the coking rate, however, the latter depends also on the amount and type of the sulfur components present in the feed [39]. ...
... The extracted ions can be further accelerated with suitable ion optics to generate thrust for small spacecraft. [11][12][13] There are three basic emitter configuration types, namely, externally wetted emitters, porous emitters, and internally wetted capillary emitters that this paper focuses on. The three of them differ in the way the propellant is supplied to the extraction sites, while all three from there on follow the same operating principle described above. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/353730642890753-1461347365836_Q64/David-Kassoy.jpg)
... Some studies have used experimental methods to analyze the effects of initiators on fuel decomposition 11−19 and heat-sink characteristics. 20,21 Chang et al. 12−14 found that adding sulfur dioxide, hydrogen peroxide, acetone, di-tert-butyl phenol, or nitromethane to fuel can effectively reduce the pyrolysis temperature and enhance pyrolysis. Meanwhile, the results indicated that the effect of the initiator is related to the properties of the initiator and the fuel. ...
... Hexaaluminate (HA) materials are highly stable at high temperatures because of their unique layered structure of alternately stacked spinel blocks separated by mirror planes [5,17] and have been used as catalysts or catalyst supports for high-temperature reactions such as methane catalytic combustion [18,19], methane reforming reaction [20], and CO methanation [5,17]. In addition, the rare-earth oxide La2O3 has been widely used as an excellent promoter for various catalysts because of its unique properties, such as neutralization of acid sites [21], stabilization of the support [22][23][24], enhancement of the catalytic performance [25], and suppression of carbon deposition by activating adsorbed H2O and CO2 [26,27]. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/281403733364736-1444103286087_Q64/Huayang-Zhu.jpg)
![[object Object]](https://i1.rgstatic.net/ii/profile.image/273546203103234-1442229905367_Q64/Michael-Kaufman-9.jpg)
... The inlet composition and velocity form the necessary initial conditions. Although the model could be extended to include axial diffusive transport, local temperature and pressure variations, and gas-phase kinetics (Zhu et al., 2007), such extensions are not needed for the flow conditions in the present experiments. ...
... Studies on environmental control should also provide guidelines for deck layout design, few studies have looked into this topic, for example, ventilation for heat and water transport [105], waste management [123,124], water recovery [125], living space arrangement [126]. ...
