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Timothy Chau

Publications and source records attributed to Timothy Chau.

23 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Thermal Management System Sizing and Mission Analysis for the SUSAN Electrofan Aircraft

This paper will detail the design, sizing, and mission analysis for the thermal management system (TMS) for the Subsonic Single Aft eNgine (SUSAN) aircraft. Previous work has defined key performance parameters (KPPs) for the electrical power system on SUSAN. These KPPs, efficiency and specific power, were assigned values for each power system component at minimum, nominal, and maximum levels of technology development. The values were based on NASA’s research in Electrified Aircraft Propulsion (EAP) technology. A similar approach was taken in this work, defining and assigning values for KPPs for each component of the TMS. These KPPs are used as inputs to the TMS analysis and sizing and establish targets for future technology development. The minimum level is based on the current state of the art, using available data on commercial off-the-shelf products from suppliers, datasheets, or testing. The nominal level is based on recent published research and on-going NASA-funded work. The maximum level represents a projection of technology performance into the future.

Electrified Aircraft↗
NASA NTRSDate not supplied

Aeropropulsive Assessment of a BLI Tail-Cone Thruster Propulsion System for the NASA Common Research Model and a Transonic Truss-Braced Wing Configuration

This paper presents an investigation into the potential benefits of a boundary layer ingestion(BLI) aft fuselage propulsion system, or tail-cone thruster (TCT), when applied to two transport category aircraft: a conventional tube-and-wing configuration based on the NASA Common Research Model (CRM) and a transonic truss-braced wing (TTBW) configuration. Through the ingestion of low-momentum flow developed over the airframe of an aircraft, the TCT propulsion system technology can reduce overall power consumption and hence fuel burn and emissions. However, an accurate assessment of this potential requires the application of high-fidelity analysis tools that can capture the relevant propulsion-airframe integration effects, at least to first order. Toward this end, the present study employs aeropropulsive analysis tools based on the Reynolds-averaged Navier-Stokes equations to estimate the power savings coefficient, measured relative to equivalent non-BLI configurations of a given airframe. Results indicate shaft power savings of 4.1% and 5.9% can be obtained for the boundary-layer ingesting TCT configuration of the CRM and TTBW, respectively. The present study also examines the coupling between airframe aerodynamics and the inlet flow distortion experienced by the TCT of a given aircraft configuration through airframe component sensitivity studies.

AATT↗
NASA NTRSDate not supplied

High-Fidelity Aeropropulsive Assessment of Distributed Electric Propulsion and Boundary Layer Ingestion for the SUSAN Electrofan

This paper presents a high-fidelity aeropropulsive assessment of the SUSAN Electrofan’s distributed electric propulsion (DEP) and boundary layer ingestion (BLI) aft fuselage turbofan technologies. This is achieved through the application of computational tools for aerodynamic and aeropropulsive design and analysis based on the Reynolds-averaged Navier-Stokes (RANS) equations. Representative aircraft models are first developed in 3D for the SUSAN Electrofan concept, a non-DEP variant, and a year 2020 technology level reference aircraft based on the Boeing 737-8. These include airframes developed through the application of RANS-based aerodynamic shape optimization, with the objective of drag minimization at cruise while subject to constant lift and zero pitching moment constraints. Wing propulsors are also included and modeled as free-flying ducted fans. These are developed through RANS-based aeropropulsive shape optimization, with the objective of shaft power minimization while subject to constant net thrust and maximum fan face Mach number constraints. An iterative power balance method is then used to trim each of the decoupled aircraft configurations, providing estimates of relative aerodynamic performance, shaft power, and range efficiency. Results also include power on and off analyses, which indicate reduced thrust-induced drag for the SUSAN Electrofan’s DEP and BLI aft fuselage turbofan propulsors when compared to those of the Boeing 737-8-like reference aircraft.

CAS↗