IoT-enabled planning, control, and execution in ETO manufacturing: dynamics, requirements, and system architecture: a case study of Brunvoll AS

Confidential until 18. May 202

Propellant-Flow-Actuated Rocket Engine Igniter

A rocket engine igniter has been created that uses a pneumatically driven hammer that, by specialized geometry, is induced into an oscillatory state that can be used to either repeatedly impact a piezoelectric crystal with sufficient force to generate a spark capable of initiating combustion, or can be used with any other system capable of generating a spark from direct oscillatory motion. This innovation uses the energy of flowing gaseous propellant, which by means of pressure differentials and kinetic motion, causes a hammer object to oscillate. The concept works by mass flows being induced through orifices on both sides of a cylindrical tube with one or more vent paths. As the mass flow enters the chamber, the pressure differential is caused because the hammer object is supplied with flow on one side and the other side is opened with access to the vent path. The object then crosses the vent opening and begins to slow because the pressure differential across the ball reverses due to the geometry in the tube. Eventually, the object stops because of the increasing pressure differential on the object until all of the kinetic energy has been transferred to the gas via compression. This is the point where the object reverses direction because of the pressure differential. This behavior excites a piezoelectric crystal via direct impact from the hammer object. The hammer strikes a piezoelectric crystal, then reverses direction, and the resultant high voltage created from the crystal is transferred via an electrode to a spark gap in the ignition zone, thereby providing a spark to ignite the engine. Magnets, or other retention methods, might be employed to favorably position the hammer object prior to start, but are not necessary to maintain the oscillatory behavior. Various manifestations of the igniter have been developed and tested to improve device efficiency, and some improved designs are capable of operation at gas flow rates of a fraction of a gram per second (0.001 lb/s) and pressure drops on the order of 30 to 50 kilopascal (a few psi). An analytical model has been created and tested in conjunction with a precisely calibrated reference model. The analytical model accurately captures the overall behavior of this innovation. The model is a simple "volume-orifice" concept, with each chamber considered a single temperature and pressure "node" connected to adjacent nodes, or to vent paths through flow control orifices. Mass and energy balances are applied to each node, with gas flow predicted using simple compressible flow equations

Propellant Flow Actuated Piezoelectric Igniter for Combustion Engines

A propellant flow actuated piezoelectric igniter device using one or more hammer balls retained by one or more magnets, or other retaining method, until sufficient fluid pressure is achieved in one or more charging chambers to release and accelerate the hammer ball, such that it impacts a piezoelectric crystal to produce an ignition spark. Certain preferred embodiments provide a means for repetitively capturing and releasing the hammer ball after it impacts one or more piezoelectric crystals, thereby oscillating and producing multiple, repetitive ignition sparks. Furthermore, an embodiment is presented for which oscillation of the hammer ball and repetitive impact to the piezoelectric crystal is maintained without the need for a magnet or other retaining mechanism to achieve this oscillating impact process

Propellant Flow Actuated Piezoelectric Igniter for Combustion Engines

A propellant flow actuated piezoelectric igniter device using one or more hammer balls retained by one or more magnets, or other retaining method, until sufficient fluid pressure is achieved to release and accelerate the hammer ball, such that it impacts a piezoelectric crystal to produce an ignition spark. Certain preferred embodiments provide a means for repetitively capturing and releasing the hammer ball after it impacts one or more piezoelectric crystals, thereby oscillating and producing multiple, repetitive ignition sparks. Furthermore, an embodiment is presented for which oscillation of the hammer ball and repetitive impact to the piezoelectric crystal is maintained without the need for a magnet or other retaining mechanism to achieve this oscillating impact process

Adult Foot and Ankle Trauma at Schroeder Mounds (11He177): A Late Woodland Period Site in Illinois

Foot and ankle trauma in adults may be accidental or caused by physical activities that increase the likelihood of injury. Little is known about the organization of labor or health of the presumed forager-farmers of the later Late Woodland (~AD 900-1150) period mortuary site of Schroeder Mounds (Henderson County, Illinois). In order to better understand the physical activities or hazards of the individuals from this site, thirty-seven adult skeletons preserving at least one essentially complete mid (metatarsals) and hind (tarsals) foot were examined for reactive changes that are consistent with traumatic injury. This data is compared to published reports from other Illinois Late Woodland sites. The study is comprised of 17 females, 14 males, and 6 skeletally unsexable adults. In the Schroeder Mounds sample, there were six cases of foot/ankle pathology (6/37, 13.5%), five of which (3/17, 17.6% females; 2/14, 14.3% males) are diagnostically traumatic injuries (5/37, 13.5%). A sixth case is a likely congenital foreshortening of a metatarsal (brachymetatarsia). There is no significant difference between the sexes in the frequency of ankle/foot trauma (p=1.000, Fisher’s test). However, given the small sample size, the results are tentative. The trauma pattern of the Schroeder mounds cases consists of the clinically infrequent tarsometatarsal (Lisfranc joint complex) high-energy misstep injuries, a vertical jump/fall (Pilon fracture), and stress (“march”) fractures of the metatarsal shafts. These injuries are consistent with a highly active and/or mobile community where trauma hazards are arguably equally experienced by both adult males and females

NASA Flexible Screen Propellant Management Device (PMD) Demonstration With Cryogenic Liquid

While evaluating various options for liquid methane and liquid oxygen propellant management for lunar missions, Innovative Engineering Solutions (IES) conceived the flexible screen device as a potential simple alternative to conventional propellant management devices (PMD). An apparatus was designed and fabricated to test flexible screen devices in liquid nitrogen. After resolution of a number of issues (discussed in detail in the paper), a fine mesh screen (325 by 2300 wires per inch) spring return assembly was successfully tested. No significant degradation in the screen bubble point was observed either due to the screen stretching process or due to cyclic fatigue during testing. An estimated 30 to 50 deflection cycles, and approximately 3 to 5 thermal cycles, were performed on the final screen specimen, prior to and between formally recorded testing. These cycles included some "abusive" pressure cycling, where gas or liquid was driven through the screen at rates that produced differential pressures across the screen of several times the bubble point pressure. No obvious performance degradation or other changes were observed over the duration of testing. In summary, it is felt by the author that these simple tests validated the feasibility of the flexible screen PMD concept for use with cryogenic propellants

Rand on the Atonement: A Critique

In March 1964, Ayn Rand sat down for an interview with Playboy. In it, Rand argued that Christ's atoning sacrifice—if it happened—was morally wrong. The author contends that Rand made a bad argument. Depending on how her words are interpreted, Rand's argument for the immorality of Christ's atonement was based on (a) at least one false premise or (b) a “bait-and-switch” fallacy. Either way, the argument fails and should be abandoned