Background, 49 CFR 179.18 specifies that, to be qualified for use, a thermal protection system of a rail tank car has to pass a 30 min torch fire test. Fabricating the 1.22 x 1.22-m specimens needed to conduct a series of torch fire tests on different formulations of a novel thermal protection system is very expensive and presents major logistical challenges because of the quantity of material needed.…, Approach, The method that was developed in the IR&D project consists of the following components: A small-scale torch fire test that is used to obtain the thermal properties of the constituent materials of a new thermal protection system, needed for input into a numerical model of the full-scale torch fire test described in the CFR A validated numerical model of the small-scale torch fire test coupled…, Accomplishments, Reasonable agreement was obtained between the measured and calculated unexposed surface temperatures, which provides a proof-of-concept for the proposed method. However, the heat transfer model needs to be extended to three dimensions so that the non-uniformity of the thermal exposure, lateral heat transfer and heat losses at the edges of the specimen can be accounted for in the calculations.…
Type: IRD Synopsis
Background, Platinum Group Metals (PGM), including platinum, palladium, and rhodium, are critical components in the catalytic conversion of pollutants produced by internal combustion engines. Historically, palladium has been less expensive than platinum while platinum was the preferred catalytically active metal in aftertreatment systems. Increasing platinum prices led to an increased use of palladium in…, Approach, In this work, ceria-supported PGM catalysts were synthesized using the atom trapping technique and compared to a commercially available alumina-supported Pt catalyst. Both Pt and Pd catalysts were prepared using this technique. Catalysts were also prepared using a lower calcination temperature at 550 °C to produce well dispersed Pt clusters without isolated single atoms. Powder catalyst samples…, Accomplishments, The ceria-supported catalysts calcined at 550 °C exhibited superior low temperature CO oxidation activity when compared to the control catalyst, two of which converted approximately 100% CO below 150 °C. At comparable loadings of Pt (i.e., 0.5 wt%), the ceria-supported Pt catalysts exhibited a T50 (temperature of 50% conversion) of CO approximately 50 °C lower than the control catalyst with co-…
Type: IRD Synopsis
Background, Battery usage is expected to grow dramatically in upcoming years across various sectors. Lithium-ion (Li-ion) batteries are among the most used energy storage technologies due to their high energy densities and specific energy capacities. These desirable characteristics also make this technology a potential safety hazard. When exposed to certain abuse factors, these batteries experience thermal…, Approach, This program was focused on performing detailed characterization of particle emissions, and limited characterization of gaseous emissions from Li-ion battery systems experiencing thermal runaway. Experiments were conducted to understand the level of variability of emissions, influence of initiation (or abuse) mechanism, and impact of battery chemistry on particle and gaseous emissions. Four…, Accomplishments, Results suggest that battery fires can result in significant particle and gaseous emissions that may be a function of initiation mechanism, battery chemistry, and cell arrangement within a module among other variables. LFP modules subjected to nail penetration yielded less emissions compared to all other cases as thermal runaway didn’t propagate to all cells within the module. Over-charging LFP…
Type: IRD Synopsis
Background, There are several different computer-aided engineering (CAE) tools in the market to assist engineers in modeling vehicle and component-level performance under various driving conditions. However, few, if any, CAE tools allow a user to evaluate the thermal and mechanical performance while also considering a vehicle’s unique control strategy. The objective of this project was to use two CAE tools…, Approach, This effort was broken into several tasks focused to improve the performance model and, later, simulate the preliminary control strategy in conjunction with the performance model. The performance model was improved by parameterizing the mechanical and thermal characteristics of key powertrain components such as engine, battery and electric machine. With the mechanical and thermal modeling…, Accomplishments, The co-simulated CAE tools were setup to allow for easy parametrization of the models such that they can be adjusted to simulate several different architectures, hardware, and controls strategies. For this application, the battery pack, motor/inverter, on-board charger, and DC-DC converter was sized and selected. The model output indicated a P2 hybrid architecture was the most optimal solution…
Type: IRD Synopsis
Background, It is well known that NO and NO2 (NOx) are emitted from internal combustion engines as a byproduct of combustion, but the NO2:NOx ratio produced can vary depending on engine specifications and operating conditions. For example, stoichiometric gasoline engines produce nearly all NO, while diesel engines may produce varying NO2:NOx ratios depending on the given operating condition. Southwest…, Approach, In this program, a baseline HNO3 decomposition system was developed, and steady-state experiments were performed to determine the kinetic parameters associated with nitric acid decomposition reactions. The kinetic experiments conducted included the determination of the activation energy and reaction order associated with HNO3 decomposition. It was expected that the reaction rate would be first…, Accomplishments, It was determined that NO2:NOx control can be achieved by varying the nitrogen containing fuel flow rate and nitric acid flow rate. It was determined that total NOx control was approximately ± 20 ppm with a target NOx setpoint of 1000 ppm, and the gas phase HNO3 concentration was maintained below 3 ppm for all operating points. The maximum NO2:NOx ratio achieved was 90 %, and the minimum was 2%.…
Type: IRD Synopsis
Background, Production volumes of electric vehicles (EVs) have increased considerably across light-duty vehicle manufacturers in the past 10-15 years as battery storage safety and efficiency continues to improve. As EVs move into every light-duty vehicle category, power and efficiency will play a differentiating role. Increased power outputs will require a more-detailed understanding of the thermal and…, Approach, A 3D CAD model was generated from an existing e-motor, namely Tesla Model 3 motor. A cooling CHT simulation model was established combining several modelling approaches. Two operating points were selected: typical real-world city driving and highest efficiency motor operation. The existing test data on this motor was used to validate the simulation. A moving reference frame (MRF) approach was…, Accomplishments, A comprehensive 3D CFD CHT tool was developed in-house for a Tesla Model 3 electric motor and the developed approach was implemented in the 3D ANSYS software package. The resulted temperature was validated with the test data. Two K-type thermocouples were mounted in the motor to measure the stator surface temperature (top and bottom side). The resulted temperatures show a good agreement with test…
Type: IRD Synopsis
Background, Since the mid-2000s, the global Automated Vehicle (AV) industry has invested more than $80 billion developing self-driving passenger, cargo, and industrial vehicles. Almost all of this research has assumed that other vehicles are manually driven. As a result, multi-vehicle maneuvers that ordinary human drivers trivially accomplish many times per day (such as highway merging, making unprotected…, Approach, The system is composed of a CV subsystem, a negotiation subsystem, and an autonomy subsystem. SwRI's novel negotiation subsystem uses the CV subsystem and a state machine to manage the status of all the vehicles involved in the maneuver, requesting and organizing the maneuver at a high level. The autonomy system of each vehicle is tasked with controlling the vehicle and providing information to…, Accomplishments, The three main possible merging scenarios were performed successfully on three of SwRI's autonomous vehicles in both phases (see attached demonstration video). The experiment was executed at SwRI’s test track and involved performing a multi-vehicle merge at approximately 25 mph. Depending on the arrival time of each vehicle, the merging vehicle would merge in front of, between, or behind the…
Type: IRD Synopsis
Background, SwRI’s Exhaust Composition Transient Operation Laboratory™ (ECTO-Lab™), generates a continuous exhaust flow through combustion of fuels and proprietary compounds, producing an exhaust gas composition that replicates the gaseous species created from the combustion of hydrocarbon (HC) fuel in an engine. The exhaust gas conditions are generated through independent, model-based controls and allow any…, Approach, In summary, the ECTO-Lab AFR controller was coded to compare the readings from an upstream UEGO O 2 sensor (λ sensor) to a downstream wide band O 2 sensor. The lambda feedback adjusted the AFR when the downstream wide band sensor detected lean A/F, indicating that the catalyst has taken up oxygen. Once lean AFR was detected downstream, the burner’s combustion conditions were changed such that the…, Accomplishments, A dual O 2 sensor A/F ratio controller was successfully developed, enabling the stoichiometric gasoline burner to dither between lean and rich conditions during operation. Initial testing indicates that this lean/rich dithering influences the extent of aging of three-way catalysts, particularly the close-coupled catalyst when one is paired with a downstream underfloor catalyst. Indeed, catalysts…
Type: IRD Synopsis
Background, Low-temperature combustion (LTC) concepts can demonstrate higher engine efficiencies than traditional pre-mixed spark-ignition combustion modes. Most LTC concepts, however, are extremely sensitive to slight changes in inlet temperature, pressure, or composition, posing challenges for practical application and transient control. One relatively new combustion strategy known as Spark Assisted…, Approach, An initial concept evaluation was carried out as a part of the prior Presidential Discretion IR project R8988. The study was limited to CFD modeling of the process in a PSA EB2 1.2 L engine with a modified compression ratio (CR) of 17:1 which demonstrated that there was a potential for engine efficiency improvement over the baseline operating with SACI + EGR. The CFD results confirmed the…, Accomplishments, The SCRE was first operated in a traditional SI combustion mode with EGR and H 2 to establish a baseline. The gross indicated thermal efficiency (gITE) results are shown in Figure 2. The results show that the engine was unstable at 33% EGR in absence of any H 2 . Upon introduction of H 2 , the engine stability and gITE could be extended further. The max gITE achieved during this testing was…
Type: IRD Synopsis
Background, The automotive industry is investing billions of dollars in electrification, and SwRI is working to extend its expertise in precision efficiency testing of internal-combustion engines to electric machines. Efficiency testing can be conducted using a vehicle mounted on a chassis dynamometer, but more precise results are obtainable by removing the drive unit (motor, gear reduction, and differential…, Approach, This project consisted of three phases: Benchmark the efficiency of an electric vehicle. Reverse-engineer the stock control strategy. Characterize the efficiency of an ex-vehicle drive unit operated by an open inverter that has been programmed with the stock control strategy. Measure the effect on inverter, drive-unit, and system efficiency of varying switching frequencies. As switching frequency…, Accomplishments, We completed Phase 1 using a Chevrolet Bolt mounted on a hub dynamometer, which measures torque at the wheel hubs, without tire slip, as shown in Figure 1. The data obtained included the inverter’s pulse-width-modulation (PWM) strategy, the switching frequency, the electrical efficiency of the inverter, the electromechanical efficiency of the drive unit, and numerous controller-are network (CAN)…
Type: IRD Synopsis
