Jon T. Zumberge

Thermal Analysis of an Integrated Aircraft Model

The INVENT Phase I efforts have focused strongly on the development of high fidelity aircraft modeling and simulation capabilities. As a part of this initiative, AFRL has undertaken the development, integration and demonstration of a mission level tip-to-tail thermal model. The major components of the integrated model include the Air Vehicle System (AVS), the Fuel Thermal Management System, the engine models, and Power Thermal Management System (PTMS). The integrated model is then flown over a complete aircraft flight mission from ground idle thru take-off, climb, cruise, descent, landing and post-flight ground hold. Having established a baseline level of performance for the aircraft PTMS system over the full mission length, the PTMS model is then exercised to investigate some possible design space trades. The trades include varying the engine bleed air demand for an aircycle design as well as comparing the air cycle performance to a representative vapor cycle design. The design trades are an effort to highlight the potential application of the integrated system model. This, first in a series of research investigations, is not constrained to actual hardware components. The components in this system are representative of modern/future aircraft. The motivation is to stimulate additional dialog and discussion as to the benefits of integrated aircraft system analysis with the long term goal of achieving a design system capable of analyzing future energy optimized aircraft.

Electromagnetic Design of Aircraft Synchronous Generator with High Power-Density

This paper discusses the methodology for the electromagnetic design of an aircraft synchronous generator with high power-density. A new method is proposed to more accurately model the air-gap of a salient pole rotor through expanding the inverse of an effective air-gap function. The corresponding magnetic fields from the rotor and stator windings, as well as the expressions of back EMF, are derived using the air-gap model. The stator inner diameter and length are designed by considering a proper cooling scheme and maximum peripheral-speed of the rotor. This allows for design of the stator winding and slot geometry, including the derivation of a formula for the stator core thickness. The air-gap and salient pole shoe face can be designed using the desired specifications for power factor and torque angle. The rotor windings and geometry are subsequently designed. Following the above procedure, a 200 KVA high power-density synchronous generator with 12 krpm rotational velocity is obtained. Finally, the design is verified and finely tuned using ANSYS RMxprt, Maxwell FEM software, and SimuLink.