Background, Composite materials have become a critical component in high-performance aerospace systems. However, fabrication of composite-based parts is still a time-consuming and expensive process, in many cases requiring significant manual labor. This project involves further development of technologies aimed at autonomous layup of prepreg composite plies—sheets of woven material, typically carbon fibers,…, Approach, The approach involves determining algorithms to autonomously define and plan robot motions for handling prepreg composite plies. The project uses a two-robot work cell where one robot is tasked to hold a ply above the mold, letting it hang loosely. A second robot uses a tool to press the ply onto the mold, conforming it to the mold geometry, which is known as draping. Since the mold geometry is…, Accomplishments, The project has successfully demonstrated composite layup of full parts in functional robot work cells. The ARM-funded project concluded successfully at USC when the robotic system performed a complete layup of a large aerospace part mounted on a rotating mold. This system made use of SwRI’s operator interface software for monitoring the layup progress. At SwRI, a work cell with two collaborative…
Type: IRD Synopsis
Background, The cylinder head is one of the most complex components of the engine, with many requirements in conflict. Cylinder head temperature control is crucial, both to minimize auto-ignition and to ensure adequate fatigue life. Aluminum fatigue strength drops quickly as operating temperatures increase. Thermo-mechanical fatigue failures can include injector bore and spark plug bore cracking, valve…, Approach, This project develops a parametric cylinder head model and applies boundary conditions from actual test data to make a comparison between the cooling effectiveness of purely sand-cast passages and hybrid passages which can optimize cooling, particularly in down-sized, turbocharged engines. Confirming and quantifying the effectiveness of hybrid-core passages will help Division 03 overcome…, Accomplishments, A printed metal insert featuring cooling pins is assembled to the cylinder head casting. Figure 3: A printed metal insert featuring cooling pins (blue) is assembled to the cylinder head casting (grey). The team developed a 1.75L, four-cylinder gasoline direct injection engine with a 0.85 bore-to-stroke ratio. The model also included a central-mounted fuel injector as compared to a traditional…
Type: IRD Synopsis
Background, CT scans at 30 G/L ash loading level Figure 1: CT scans at 30 G/L ash loading level. Particulate matter (PM) emissions from internal combustion engines have been of great interest to legislators. When evaluating the relative contributions of diesel- and gasoline-powered vehicles to ambient PM in the United States in 2000, the U.S. EPA concluded that diesel-powered vehicles contributed 62 percent…, Approach, This project consisted of evaluating various engine- and burner-based accelerated ash loading techniques. Each technique was compared to a non-accelerated, field generated GPF for their ash deposition profile and GPF pressure drop performance., Accomplishments, Field returned GPF CT scan Figure 2: Field returned GPF CT scan. The goal of this study was to achieve two results: gain capabilities in GPF accelerated ash loading and determine an acceptable accelerated ash loading approach that replicates real world ash deposition mechanisms for GPFs. The burner-based method produced the lowest density ash plug layer with a parabolic deposition profile, as…
Type: IRD Synopsis
Background, The purpose of this project was to examine the effect of engine lubricant oil on particle emissions from a modern gasoline direct injection (GDI) light-duty vehicle. In recent years, GDI engines have been widely adopted by manufacturers in the light-duty market to meet stringent fuel economy and emissions regulations. Despite improved fuel economy and lower carbon dioxide emissions, these engines…, Approach, Two lubricating engine oils with widely differing physical and chemical properties — one with low volatility and low ash content (Oil A), and another with high volatility and high ash content (Oil B) were tested. Testing included three repeats of cold-start FTP-75 followed by hot-start US06 for each engine oil. SwRI’s Direct Electronic Vehicle Control (DEVCon™) driving method was utilized to…, Accomplishments, Results from this program showed that particle emissions could be influenced by lubricating engine oil properties. PM mass, solid PN, total PN and ash number emissions showed an increase with the oil having higher volatility and ash content (Oil B). For composite FTP-75, Oil B showed approximately 17 percent more PM mass and total PN emissions compared to Oil A. Another significant observation…
Type: IRD Synopsis
Background, Simulation and modeling of internal combustion engines has become the standard in engine development by shortening development time and eliminating some of the hardware iterations that were required twenty years ago. SwRI has developed a combustion model (HEDGE mechanism) for gasoline engines as part of the HEDGE-III consortium and has been applied in 3D Computational Fluid Dynamics (CFD)…, Approach, Three simulations were conducted concurrently: combustion CFD, thermal FEA and cooling CFD. Because the cyclic variation of the parameters for thermal FEA and cooling CFD is minor, both simulations were conducted under a steady-state mode. The combustion CFD was conducted under transient conditions due to highly transient process inside the combustion chamber. For the interaction, data was…, Accomplishments, A diesel and a gasoline engine were modelled using this conjugate heat transfer (CHT) technique. Heat transfer models based on experience-based SwRI analysis methods were also setup for both engines. The conjugate heat transfer method demonstrated better temperature agreement than the experience-based analysis methods, a 12.5 percent improvement in accuracy on average. The combustion model for…
Type: IRD Synopsis
Background, The objective of the proposed research is to identify the critical parameters that determine the performance of high pulse energy turbocharger systems. The term “high pulse energy turbocharger” refers to a turbocharger that provides exceptionally high isentropic efficiency when operated under highly pulsed flows. High pulse energy turbochargers are typically twin scroll turbochargers where the…, Approach, Engine tests would be conducted using multiple turbochargers, exhaust manifold designs, and test engines. The results of these tests will provide a detailed characterization of gas flow, turbine speed, and turbine performance. Data from the detailed characterization would be used to set boundary conditions for the CFD simulation, and the model would be evaluated to determine how well it matched…, Accomplishments, A total of eight engine, turbocharger, and exhaust manifold configurations were tested, including high-speed pressure measurements in multiple locations around the turbine and compressor. The experimental evaluations found that the exhaust manifold geometry had a significant contribution to the measured turbine efficiency. Exhaust manifolds with less pre-turbine volume improved the turbine…
Type: IRD Synopsis
Background, Decane molecule in zeolite cage Figure 1: Decane molecule in zeolite cage. The objective of the project was to explore the kinetic modeling capabilities of Rhodium to predict the performance of zeolite catalysts in adsorption and desorption of hydrocarbons. The second part of the project was to washcoat catalyst cores with the best zeolite candidates and conduct hydrocarbon storage testing using…, Approach, We proposed using the Rhodium tool to screen various zeolites under conditions that will approximate the exhaust gas environment for this application (Figure 1). The most promising candidate zeolites were identified using the Rhodium data, and wash-coated samples of these candidates were prepared for laboratory validation tests. SwRI utilized the USGR system to conduct experiments on the zeolite…, Accomplishments, Of the four zeolites selected, ZSM-5 with high silica/alumina ratio showed superior hydrocarbon storage. Rhodium could predict the storage trend for the zeolites. However, there were several discrepancies between the simulations and the test results. The simulations did not account for strong bonds such as H-bonds and covalent bonds. There was no flow direction; therefore, simulations were unable…
Type: IRD Synopsis
Background, Low Speed Pre-ignition (LSPI) is a potentially destructive form of abnormal combustion present in turbocharged, direct injection, spark-ignition engines. Although LSPI is stochastic in nature, SwRI has developed a test methodology for quantifying the impact of engine conditions, fuels and oils on LSPI activity using an engine on a test stand. Suppliers of engine parts – specifically pistons and…, Approach, To achieve this objective, two evaluations were performed. The first evaluation entailed disassembly and reassembly of a test engine with the original parts, simulating an engine inspection. A previously-stabilized LSPI test engine was disassembled by removing the head, pistons and rings and then rebuilding it using the same, uncleaned parts. The three tests that followed the rebuild did not show…, Accomplishments, Results confirmed that the engines used for LSPI can be disassembled, cleaned and reassembled without the need to re-stabilize and without affecting the LSPI activity, making it a suitable platform for engine hardware evaluations.
Type: IRD Synopsis
Background, operator uses the demonstration tool to indicate key points in the desired robot path Figure 1: This test work cell is used to evaluate visual demonstration programming methods. The operator uses the demonstration tool to indicate key points in the desired robot path. A graphical display allows the operator to interactively create the sequence of path points and review the planned robot motion…, Approach, This project is investigating an alternative user-friendly teaching method utilizing camera-based tracking of operator task demonstrations. This solution can be deployed across a wide range of applications, requiring no specialized robot hardware. The test workcell used for this project includes a collaborative robot, a 3D sensor mounted near the robot end effector, and an operator demonstration…, Accomplishments, A graphical interface provides feedback during the programming process Figure 2: A graphical interface provides feedback during the programming process. Additional software enhancements are planned to adjust the raw demonstration input to automatically align with observed part features. This new visual programming method will be compared against existing “hands-on” and pendant-based programming…
Type: IRD Synopsis
BACKGROUND, The quality and the properties of parts manufactured by the selective laser melting (SLM) additive manufacturing (AM) process are strongly influenced by many factors. Key among these factors is the impacts associated with the metal powders that are used as input material. The importance of the metal powder characteristics (i.e. particle shape, size distribution, grain size, impurities, density,…, APPROACH, The overall objective of the proposed work is to investigate engineered platelets produced by vacuum roll coating as an innovative source material for SLM-AM process. The specific aims are to 1) synthesize engineered platelets using a vacuum roll coating process (Ti-6Al-4V, 10 micron hexagonal shaped), 2) manufacture SLM-AM test parts using the engineered platelets and control SLM-AM test parts…, ACCOMPLISHMENTS, We have just begun the third quarter of the project. We established the facilities for a vacuum roll coating method to prepare appreciable quantities of engineered platelets through top-down physical vapor deposition of multilayer films on embossed substrates. We developed processes for producing engineered titanium alloy platelets for SLM-AM that utilized a polyethylene terephthalate (PET)…
Type: IRD Synopsis
