System Exergy: System Integrating Physics of Launch Vehicles and Spacecraft

Abstract

System Engineering of launch vehicles and spacecraft is a challenging and complex under taking. There are many diverse systems which must be integrated and balanced to produce an effective design. This involves a multiplicity of individual engineering relationships that are difficult to integrate and even more difficult to define in a best balance. Integration efforts involve many different approaches from process management to mass balance. But these approaches either do not directly address the launch vehicle or spacecraft performance or require many adjustments to be made to discover a balance. The system integrating physics, derived from the fundamental physics of the system, is the key to identifying a fully integrated system performance measure. Launch vehicles and spacecraft are thermodynamic systems with performance defined by thermodynamic properties. Thus, thermodynamic exergy, which integrates all of the systems thermodynamic properties, provides the system integrating relationships. This provides a basis for determining the most efficient design from among many different configuration options and for guiding the design activities from an integrated system level. This paper explores the current physics relationships used in launch vehicle system design and demonstrates that thermodynamic exergy provides a more explicit and complete approach to system integration.

Systems Engineering Principles and Hypotheses

“…This principle shows there is a minimal path of work that balances the system work parameters in accomplishing its function. Exergy is an expansion of this principle and research on exergy efficiency of a rocket indicates that an optimal system, with an objective of thermodynamic efficiency, defines system efficiency across multiple configurations (Watson 2018a). This result has not previously been achievable in a quantifiable manner.…”

Exergy-based modeling framework for hybrid and electric ground vehicles

“…In the vehicular field, a plethora of work can be found in the context of aircrafts, rockets, and launch vehicles [9], [10], [11], [12], [13]. In particular, [9] and [10] applied the availability principle for the design, analysis, and optimization of hypersonic aircrafts.…”

Mean-value exergy modeling of internal combustion engines: characterization of feasible operating regions

“…Exergy-based modeling is a well-known concept in aerospace engineering, where diverse systems must be integrated and balanced to produce effective designs. In [3] and [4], the authors propose an availability analysis for rockets and launch vehicles, respectively. The design and optimization of hypersonic aircrafts is tackled in [5] and [6].…”