Predictive GT-Power Simulation for VNT Matching on a 1.6 L Turbocharged GDI Engine
Robertson, D., G. Conway, C. Chadwell, J. McDonald, D. Barba, M. Stuhldreher, AND A. Birchett. Predictive GT-Power Simulation for VNT Matching on a 1.6 L Turbocharged GDI Engine. SAE Technical Paper Series. SAE International, Warrendale, PA, , 16, (2018). https://doi.org/10.4271/2018-01-0161
The purpose of this work was to develop and validate a 0d combustion/1d gas dynamics model of an advanced gasoline, light-duty-vehicle, direct injection (GDI) engine equipped with a variable nozzle turbine (VNT) turbocharger; low-pressure-loop, cooled external exhaust gas recirculation (EGR); continuous variable intake valve lift (CVVL), and variable intake and exhaust valve timing (VVT). This work was conducted as part of the U.S. EPA's Light-duty Vehicle GHG Midterm Evaluation.
The thermal efficiency benefits of low-pressure (LP) exhaust gas recirculation (EGR) in spark-ignition engine combustion are well known. One of the greatest barriers facing adoption of LP-EGR for high power-density applications is the challenge of boosting. Variable nozzle turbines (VNTs) have recently been developed for gasoline applications operating at high exhaust gas temperatures (EGTs). The use of a single VNT as a boost device may provide a lower-cost option compared to two-stage boosting systems or 48 V electronic boost devices for some LP-EGR applications. A predictive model was created based on engine testing results from a 1.6 L turbocharged gasoline direct injection (GDI) engine. The model was tuned so that it predicted burn-rates and end-gas knock over an engine operating map with varying speeds, loads, EGR rates and fuel types. Using the model, an assessment of VNT performance was performed using compressor and turbine maps made available from Honeywell Transportation Systems. Results show that the single VNT device supports LP-EGR across the operating map while maintaining realistic full-load performance and maintaining or improving upon thermal efficiency compared to a twin-scroll turbocharger. This work was done as part of the Environmental Protection Agency’s continuing assessment of advanced light-duty automotive technologies to support setting appropriate national greenhouse gas standards.
PREDICTIVE GT-POWER SIMULATION FOR VNT MATCHING ON A 1.6 L TURBOCHARGED GDI ENGINE Exit
Record Details:Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
AIR AND ENERGY MANAGEMENT DIVISION
DISTRIBUTED SOURCE AND BUILDINGS BRANCH