Background, Instrumentation for space and high vacuum applications is typically composed of an assembly of metallic and ceramic parts. Attachment of these dissimilar materials to one another may be accomplished in a variety of ways. To minimize parts count and mass without sacrificing performance, hermetic bonds between metals and ceramics can be made by brazing the joints together. One of the challenges…, Approach, A series of AM test specimens and assemblies of increasing complexity will be fabricated and tested. Individual AM parts, AM parts welded to one another and to conventionally manufactured parts, and finally AM parts bonded to ceramics will all be assessed. Performance characteristics evaluated will include: vacuum outgassing and quantification of virtual leaks, leak tightness of joints, and…, Accomplishments, Titanium AM tubes were manufactured and tested. Testing of these parts revealed good machinability and leak tightness up to ultra-high vacuum levels. After this baseline performance was verified, the program has focused on creation of more complex assemblies with AM components. A test fixture was designed to enhance the capabilities of the metal powder bed fusion machine. This fixture modifies…
Type: IRD Synopsis
Background, Among the first steps of any planetary surface investigation is to construct a mosaic, which facilitates innumerable geologic and geophysical studies. This holds regardless of whether mosaics already exist: Ever-higher-resolution mosaics enable new studies and almost always quickly supersede the previous generation. We worked to develop workflow to create global 6 meters/pixel Mars…, Approach, We began with a basic, iterative process of creating semi-automated control networks. A control network takes multiple images, identifies common features, and determines how the a priori spacecraft and camera pointing information must be altered in order to have those features project to the same location. Once that is solved, the images can be re-projected with our new solution and mosaicked.…, Accomplishments, We succeeded in developing a solid workflow that works for Mars CTX images. We are cautious here as to how well this workflow might be generalized to other data and other bodies because the specific camera and imaging campaign for MRO CTX are ideal for creating even, high quality mosaics. We modified our original approach to remove much of the iterative component, which greatly reduced the time…
Type: IRD Synopsis
Background, Liquefaction resistance of a specific soil deposit is most effectively studied using laboratory tests. The discrete element method (DEM) provides powerful capabilities to simulate laboratory-scale tests of granular media. Direct simple shear (DSS) tests are increasingly used in characterizing soil behavior under cyclic loading simulating earthquake loading. DEM models are particularly well-suited…, Approach, The objectives of this project were to 1) develop a numerical test procedure for simulation of laboratory scale cyclic DSS tests of granular soil under undrained conditions, 2) validate the numerical model with available laboratory DSS test data and numerical modeling results on uniform diameter glass beads, and 3) develop a procedure to accurately simulate DSS tests of real soil with a particle…, Accomplishments, The model was used to simulate laboratory tests of glass beads of uniform diameter. The PFC modeled responses for cyclic shear testing — represented by the standard curves, shear stress vs. vertical stress, shear stress vs. strain, and excess pore pressure generation — replicated similar behaviors observed in laboratory tests and modeling by Dabeet et al. (2014), as shown in Figure 1. The model…, (a), PFC model simulation and, (b), Dabeet et al.
Type: IRD Synopsis
Background, Managing water resources in arid and semi-arid dryland landscapes is increasingly important due to pressures from escalating water demand, limited water availability, and uncertainty resulting from global climate change. Groundwater is an important component of available water resources, and appropriate resource management requires that replenishment through recharge be accurately determined. In…, Approach, The project has two separate but related tasks: (i) analysis of the data gathered by satellite based sensors for upland topography to better understand the limitations and opportunities offered by the data and (ii) development of methodologies to use the satellite sensed data to constrain recharge calculations. The first task considers arid and semiarid North America, especially the southwestern…, Accomplishments, The project team identified two additional candidate radar‑based satellite data sources early in the project. The Soil Moisture and Ocean Salinity (SMOS) dataset has L‑band emittance data, similar to SMAP data and with similar resolution, but obtained with a different observation strategy over a much longer historical period. The Sentinel-1 dataset is based on polarized backscatter from C-band…
Type: IRD Synopsis
Background, Engine piston rings that are being targeted for possible fuel economy gains using low-friction coatings. Figure 1: Engine piston rings that are being targeted for possible fuel economy gains using low-friction coatings. Aggressive greenhouse gas and fuel economy regulations require that automakers continually improve the fuel economy of new vehicles. Consequently, automakers are requiring their…, Approach, The technique for evaluating the low-friction coating is the implementation of SwRI’s Direct Electronic Vehicle Control (DEVCon™) system combined with a high precision chassis dynamometer. DEVCon is used to apply an electronic accelerator pedal position (APP) signal directly to the vehicle’s engine control unit (ECU) and eliminates the variation normally introduced by a human driver. Figure 2…, Accomplishments, The test vehicle’s fuel economy has been measured from multiple vehicle configurations using the Federal Test Procedure (FTP-75) and Highway Fuel Economy Test (HwFET) vehicle certification cycles. The first three baseline configurations were used to establish a fuel economy datum and to measure the influence of the piston ring installation process. Baseline configurations were used to bracket…
Type: IRD Synopsis
Background, Biomechanical analysis through 3D motion capture is a valuable tool for accurately quantifying human movement. The measurements gathered by these means can be used to improve performance, increase efficiency, and identify potential injury risks for sports athletes and tactical athletes. While most 3D motion capture systems use reflective markers and specialized cameras, markerless systems are…, Approach, To support validation and tracking of the mobile cameras, a marker-based motion capture system will be leveraged. This system uses the following hardware: Six 5 megapixel infrared cameras Eight 2.2 megapixel infrared cameras The same marker cluster model and labeling skeleton will be used as with previous internal research and external clients. A second camera system consisting of two USB 3.0…, Accomplishments, The two camera systems have been installed. The Initial capture sessions began on a single subject. These captures are now being processed to generate the validation data on both the subject (joint centers and joint angles) and the mobile cameras. This data will be used to start the process of selecting and refining the computer vision algorithms that will solve for the mobile cameras’ motions…
Type: IRD Synopsis
Background, Starting with engine model year 2016, exhaust particle sensors are required for on-highway diesel engines in the United States for onboard diagnostics to detect component failure or exceedance in particle emissions relative to a regulatory threshold limit. This trend is expected to continue for gasoline direct injection engines as well as for non-road engines in the near future. Particle sensors…, , Particle concentration voltage diagram Figure 1: This simplified drawing represents the voltage breakdown (VB) and/or voltage-versus-current (VI) relationship between two electrodes as a function of particle concentration presence., Approach, The novelty element of the new design relies on exploiting the relationship between voltage breakdown (VB) and/or voltage-versus-current (VI) relationship between two electrodes as a function of particle concentration presence, as simplified in Figure 1. The flowing gas and aerosol mixture would alter the properties of the dielectric medium between the two electrodes resulting in unique…, Accomplishments, This work serves as an example of collaboration combining the skillsets of two SwRI groups. It directly contributes to SwRI’s existing Particle Sensor Performance & Durability (PSPD) consortium by advancing the state of knowledge in the field of particle sensing. The work opens a potential venue of collaboration with the Department of Defense, Department of Energy, and the U.S. Environmental…
Type: IRD Synopsis
Background, The objective of this proposed project is to develop an understanding of the impact of swirl distortion on centrifugal compressor performance and develop a method to analyze it experimentally and numerically. The aerodynamic performance of a centrifugal compressor depends strongly on the velocity and total pressure profile of the flow when it arrives at the inlet. Thus, one of the primary goals…, Approach, Computational fluid dynamic (CFD) simulations will be used to quantify the uniformity of the velocity profile and amount of swirl at the compressor inlet plane for different piping layouts. The effect of those layouts on the performance of a generic impeller wheel will then be tested in the Single Stage Test Rig (SSTR). The data from the experimental study will be used to validate the CFD…, Accomplishments, To date, the SSTR has been used to test two customer-fabricated impellers since the SwRI-designed impeller took over 6 months to complete. Figure 1 shows the SSTR assembled with an elbow placed 1 pipe diameter upstream of the impeller while Figure 2 shows the setup with an elbow located 10 pipe diameters upstream. Custom-designed Impeller for Inlet Distortion Studies Figure 1: Custom-designed…
Type: IRD Synopsis
Background, Failed piston Figure 1: A failure related to stochastic pre-ignition. Low speed pre-ignition (LSPI), also known as stochastic pre-ignition (SPI), is an abnormal, potentially destructive form of combustion that occurs in gasoline spark-ignited engines when the air-fuel mixture is ignited prematurely. LSPI most commonly occurs in turbocharged direct-injection engines that are operating at low…, Approach, The objective of this research was to determine if LSPI can be predicted based on macro-scale analysis across all SwRI-owned LSPI datasets. Advanced analyses, based on our extensive expertise in state-of-the-art machine learning and deep learning techniques, were used to identify whether distinct classes of LSPI exist, evaluate the basis for predictive models that can be used to detect incipient…, Accomplishments, Data obtained as part of the Pre-ignition Prevention Program consortium was obtained, cleansed, converted, and inspected. Analyses were performed on these data to determine LSPI frequency and type among the various testing conditions. Feature importance was explored to determine which measurements have the strongest correlation with LSPI events. An automated machine learning pipeline was…
Type: IRD Synopsis
Background, The primary objective of the project was to develop and validate an approach for measuring the heat release rate (HRR) versus time curve for room fire tests conducted in building 166 based on a combination of inverse compartment fire modeling and oxygen consumption calorimetry. More specifically, the intent was to demonstrate that SwRI has (or can develop) the capability to perform room fire…, Approach, The approach for the project consisted of the following tasks: Install the necessary probes and instrumentation in the exhaust duct so that HRR can be measured using oxygen consumption calorimetry Perform a calibration test with a 1,500 kW propane burner (the highest diffusion flame gas burner available in the department) placed on the floor of building 166, directly below the 6-ft wide opening…, Accomplishments, The proposed approach to use inverse modeling turned out to be impractical due to the time needed to complete the necessary iterations of CFD calculations. However, the calibration test allowed us to validate FDS and demonstrate that HRRs up to 15 MW can be measured accurately by installing a hood of specific dimensions in building 166. The CFD simulations were used to determine the minimum…
Type: IRD Synopsis
