Two variations on open cycle Brayton systems were analyzed, consisting of an “airborne” thrust producing propulsion system, and a “ground-based” power generation system. Both of these systems have some mole fraction of He, Ne, or Ar injected into the flow path at the inlet, and some fraction of monatomic gas recuperated and at the nozzle exit to be re-circulated through the system. This creates a working medium of an air-monatomic gas mixture before the combustor, and a combustion products-monatomic gas mixture after combustor. The system’s specific compressor work, specific turbine work, specific net power output, and thermal efficiency were analyzed for each case. The most dominant metric for performance is the thermal efficiency (η_sys), which showed a significant increase as the mole fraction of monatomic gas increased for all three gas types. With a mole fraction of 0.15, there was a 2-2.5% increase in the airborne system, and a 1.75% increase of the ground-based system. This confirms that “spiking” any open Brayton system with monatomic gas will lead to an increase in performance. Additionally, both systems showed an increase in compressor and turbine work for a set temperature difference with He and Ne, which can additionally lead to longer component lifecycles with less frequent maintenance checks.
The cost analysis essentially compares the operating cost of a standard system with the operating cost of the monatomic gas “spiked” system, while keeping the internal mass flow rate and total power output the same. This savings is denoted as a percent of the standard system with %NCS. This metric lumps the cost ratio of the monatomic gas and fuel (MGC/FC) with the fraction of recuperated monatomic gas (RF) into an effective cost ratio that represents the cost per second of monatomic gas injected into the system. Without recuperation, the results showed there is no mole fraction of any monatomic gas type that yields a positive %NCS for a reasonable range of current MGC/FC values. Integrating recuperation machinery in an airborne system is hugely impractical, effectively meaning that the use of monatomic gas in this case is not feasible. For a ground-based system on the other hand, recuperation is much more practical. The ground-based system showed that a RF value of at least 50% for He, 89% for Ne, and 94% for Ar is needed for positive savings. This shows that monatomic gas could theoretically be used cost effectively in a ground-based, power-generating open Brayton system. With an injected monatomic gas mole fraction of 0.15, and full 100% recuperation, there is a net cost savings of about 3.75% in this ground-based system.
Today, the vision of Commercial Supersonic Travel is often dreamed possible with innovation. Modern tech-business plans to reinvent commercial SuperSonic Transport (SST), while gaining reliable venture capital investment and proactive social backing. However, the concept’s global viability remains questionable, as regulation opposes its integrability. As a result, SST has become industrially forgotten. This research paper challenges the neglect of SST through routing optimizations derived from an industry’s collective research, while outlining decisive use-cases. Initially, this paper describes the difficulty in SST’s integration through its logistical tasks, demanding designs, and lacking efficiency. After that, the paper defines an optimization strategy, through software-analyzed flight paths, for overall supersonic operations. This strategy was proven to shorten established SST flights by 6%, while enabling the implementation of newfound SST paths. Here, optimization averaged 3.3% on density-derived routes and 5.4% on software-derived routes. More importantly, this paper demonstrated routing optimization enables MACH 1.6 aircraft to achieve MACH 2 flight times. Further, this paper attempts to justify SST through an analysis of its market, financials, and social perspectives. With that, the paper justifies an ideal SST customer earns 630$/hr, while such measurements vary amongst flight types. Finally, this paper conceptualizes that SST, with optimization, promises a noteworthy business, while developments in aircraft designs may revamp the aerospace industry completely.
The objective of this report is to discover a skyhook’s ability to change the plane of another spacecraft’s orbit while ensuring that each vehicle’s orbital energy remains constant. Skyhooks are a proposed momentum exchange device in which a tether is attached to a counterweight at one end and at the other, a capturing device intended to intercept rendezvousing spacecraft. Trigonometric velocity vector relations, along with objective comparisons to traditionally proposed uses for skyhooks and gravity-assist maneuvers were responsible for the ultimate parameterization of the proposed energy neutral maneuver. From this methodology, it was determined that a spacecraft’s initial relative velocity vector must be perpendicular to, and rotated about the skyhook’s total velocity vector if it is to benefit from an energy neutral plane change maneuver. A quaternion was used to model the rotation of the incoming spacecraft’s relative velocity vector. The potential post-maneuver spacecraft orbits vary in their inclinations depending on the ratio between the skyhook and spacecraft’s total velocities at the point of rendezvous as defined by the parameter called the alpha criterion. For many cases, the proposed maneuver will serve as a desirable alternative to currently practiced propulsive plane change methods because it does not costly require a substantial amount of propellant. The proposed maneuver is also more accessible than alternative methods that involve gravity-assist and aerodynamic forces. Additionally, by avoiding orbital degradation through the achievement of unchanging total orbital energy, the skyhook will be able to continually and self-sustainably provide plane changes to any spacecraft that belong to orbits that abide by the identified parameters.
This thesis considers common definitions of uninstalled thrust, rigorous thrust derivations, and the significance of thrust definitions and derivations on air vehicle thrust-drag accounting methodology. This physics-based control volume approach to propulsive force accounting highlights differences in the application of control volume methods from different sources and summarizes common installation corrections. Certain combinations of thrust and installation corrections in practice lead to force accounting mistakes which can propagate in legacy aerodynamics and propulsion codes. The work concludes by proposing a simplified propulsive force accounting methodology applicable to many (not all) situations, a potential missing installation correction, and a procedural solution to the confusing and messy practice of aero-propulsive force accounting