Search Results

The objective of the study is to characterize combustion and performance of a multi-cylinder turbocharged direct-injection (DI) diesel engine at altitude conditions according to the International Standard Atmosphere (ISA). Experiments were performed on the 6.6-liter turbocharged DI diesel engine, a model similar to that of the Army’s Joint Light Tactical Vehicle. The engine was installed in the US Army Research Laboratory Small Engine Altitude Research Facility. Outside air temperature (OAT) and outside air pressure were independently controlled to match the ISA-OAT at selected altitude conditions: sea level, 1524, 3048, and 4572 m. The test engine is equipped with a single-stage variable nozzle turbocharger and Bosch CRIN 3 common-rail injection system. Three load conditions (i.e., low, mid, and high) were selected at 1400 rpm to investigate combustion and performance of the engine using Jet Propellant-8 (JP-8) fuel.

The applications of unmanned aerial vehicles (UAV) are growing exponentially with advances in hybrid powertrain architecture design tools. The thermal management system (TMS) as an integral part of the powertrain architecture greatly affects the system performance of aerial vehicles. In this study, a comparative analysis of two types of thermal management technologies for a UAV with a series-hybrid powertrain architecture was performed. Conventional TMS based on single-phase (no phase change) cooling technologies using air and liquid (e.g., antifreeze water mixture and oil) as heat transfer fluid has been commonly used because of simple design and operation, although it is considered to be inefficient and bulky. As advanced designs, phase change-based TMS is being slowly adopted although it promises superior cooling capabilities.