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- Mechanical engineering (1)
- Microchannel heat exchanger (1)
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- Optical metrology (1)
- Organic Rankine cycle (1)
- Perceived loudness (1)
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Articles 1 - 9 of 9
Full-Text Articles in Engineering
Experimental Characterization Of Thermal-Hydraulic Performance Of A Microchannel Heat Exchanger For Waste Heat Recovery, James Yih, Hailei Wang
Experimental Characterization Of Thermal-Hydraulic Performance Of A Microchannel Heat Exchanger For Waste Heat Recovery, James Yih, Hailei Wang
Mechanical and Aerospace Engineering Faculty Publications
Given size and performance advantages, microchannel heat exchangers are becoming increasingly important for various energy recovery and conversion processes. In this study, detailed experimental measurements were conducted to characterize flow and heat transfer performance of a microchannel heat recovery unit (HRU) manufactured using standard photochemical etching and diffusion bonding processes. According to the global flow and temperature measurement, the HRU has delivered the predicted thermal performance under various oil and air flow rates. As expected, the heat transfer effectiveness varies between 88% and 98% for a given air and oil flow rates while it increases with air inlet temperature due …
Gelatine Cavity Dynamics Of High-Speed Sphere Impact, Akihito Kiyama, Mohammad M. Mansoor, Nathan B. Spiers, Yoshiyuki Tagawa, Tadd T. Truscott
Gelatine Cavity Dynamics Of High-Speed Sphere Impact, Akihito Kiyama, Mohammad M. Mansoor, Nathan B. Spiers, Yoshiyuki Tagawa, Tadd T. Truscott
Mechanical and Aerospace Engineering Faculty Publications
We investigate the impact and penetration of a solid sphere passing through gelatine at various impact speeds up to 143.2 m s-1 Tests were performed with several concentrations of gelatine. Impacts for low elastic Froude number Fre a ratio between inertia and gelatine elasticity, resulted in rebound. Higher Fre values resulted in penetration, forming cavities with prominent surface textures. The overall shape of the cavities resembles those observed in water-entry experiments, yet they appear in a different order with respect to increasing inertia: rebound, quasi-seal, deep-seal, shallow-seal and surface-seal. Remarkably, similar to the We – Bo phase …
Secondary Electron Yield Measurements Of Carbon Nanotube Forests: Dependence On Morphology And Substrate, Brian Wood, Jordan Lee, Gregory Wilson, T. -C. Shen, Jr Dennison
Secondary Electron Yield Measurements Of Carbon Nanotube Forests: Dependence On Morphology And Substrate, Brian Wood, Jordan Lee, Gregory Wilson, T. -C. Shen, Jr Dennison
Journal Articles
Total, secondary, and backscatter electron yield data were taken with beam energies between 15 eV and 30 keV, in conjunction with energy emission data, to determine the extent of suppression of yield caused by carbon nanotube (CNT) forest coatings on substrates. CNT forests can potentially lower substrate yield due to both its inherently low-yield, low-atomic number (Z) carbon composition, and its bundled, high-aspect ratio structure. Rough surfaces, and in particular, surfaces with deep high-aspect-ratio voids, can suppress yields, as the electrons emitted from lower lying surfaces are recaptured by surface protrusions rather than escaping the near-surface region. Yields of multilayered …
Wireless Antenna Detection Of Electrostatic Discharge Events, Allen Andersen, Jr Dennison
Wireless Antenna Detection Of Electrostatic Discharge Events, Allen Andersen, Jr Dennison
Journal Articles
Wireless intraspacecraft communication technology is being developed for signal transfer on space missions to save weight and simplify the design. One consideration for this new technology is its interaction with space environmentinduced electrostatic discharges (ESDs). The short time scales of spacecraft ESD events result in broad frequency band signals that can interact with high-frequency wireless antennas. These interactions present a source of signal noise. However, they also present a possibility of in-flight wireless ESD monitoring. We present laboratory measurements of arcing on common spacecraft insulators using commercially available single-band 2.4-GHz and dual-band 2.4-/5.8-GHz Wi-Fi antennas. These wireless detections are shown …
How Vision Governs The Collective Behaviour Of Dense Cycling Pelotons, J. Belden, Mohammad M. Mansoor, A. Hellum, S. R. Rahman, A. Meyer, C. Pease, J. Pacheco, S. Koziol, Tadd T. Truscott
How Vision Governs The Collective Behaviour Of Dense Cycling Pelotons, J. Belden, Mohammad M. Mansoor, A. Hellum, S. R. Rahman, A. Meyer, C. Pease, J. Pacheco, S. Koziol, Tadd T. Truscott
Mechanical and Aerospace Engineering Faculty Publications
In densely packed groups demonstrating collective behaviour, such as bird flocks, fish schools or packs of bicycle racers (cycling pelotons), information propagates over a network, with individuals sensing and reacting to stimuli over relatively short space and time scales. What remains elusive is a robust, mechanistic understanding of how sensory system properties affect interactions, information propagation and emergent behaviour. Here, we show through direct observation how the spatio-temporal limits of the human visual sensory system govern local interactions and set the network structure in large, dense collections of cyclists. We found that cyclists align in patterns within a ± 30° …
A Multi-Fidelity Prediction Of Aerodynamic And Sonic Boom Characteristics Of The Jaxa Wing Body, Forrest L. Carpenter, Paul G. A. Cizmas, Christian R. Bolander, Ted N. Giblette, Doug F. Hunsaker
A Multi-Fidelity Prediction Of Aerodynamic And Sonic Boom Characteristics Of The Jaxa Wing Body, Forrest L. Carpenter, Paul G. A. Cizmas, Christian R. Bolander, Ted N. Giblette, Doug F. Hunsaker
Mechanical and Aerospace Engineering Student Publications and Presentations
This paper presents a detailed comparison between the linear panel solver PANAIR A502 and the in-house Navier–Stokes solver UNS3D for a supersonic low-boom geometry. The high-fidelity flow solver was used to predict both the inviscid and laminar flow about the aircraft geometry. The JAXA wing body was selected as the supersonic low-boom geometry for this study. A comparison of the undertrack near-field pressure signatures showed good agreement between the three levels of model fidelity along the first 0.8L of the signature. Large oscillations in the PANAIR results were observed. The PANAIR discrepancies were traced back to violations of the …
A High Magnification Uv Lens For High Temperature Optical Strain Measurements, Robert S. Hansen, Trevor J. Bird, Ren Voie, Katharine Z. Burn, Ryan B. Berke
A High Magnification Uv Lens For High Temperature Optical Strain Measurements, Robert S. Hansen, Trevor J. Bird, Ren Voie, Katharine Z. Burn, Ryan B. Berke
Mechanical and Aerospace Engineering Faculty Publications
Digital Image Correlation (DIC) measures full-field strains by tracking displacements of a specimen using images taken before and after deformation. At high temperatures, materials emit light in the form of blackbody radiation, which can interfere with DIC images. To screen out that light, DIC has been recently adapted by using ultraviolet (UV) range cameras, lenses, and filters. Before now, UV-DIC had been demonstrated at the centimeter scale using commercially available UV lenses and filters. Commercial high-magnification lenses using visible light have also been used for DIC. However, there is currently no commercially available high-magnification lens that will allow images to …
Water Walking As A New Mode Of Free Surface Skipping, Randy Craig Hurd, Jesse Belden, Allan F. Bower, Sean Holekamp, Michael A. Jandron, Tadd T. Truscott
Water Walking As A New Mode Of Free Surface Skipping, Randy Craig Hurd, Jesse Belden, Allan F. Bower, Sean Holekamp, Michael A. Jandron, Tadd T. Truscott
Mechanical and Aerospace Engineering Faculty Publications
Deformable elastomeric spheres are evaluated experimentally as they skip multiple times over a lake surface. Some spheres are embedded with small inertial measurement units to measure the acceleration experienced during water surface impact. A model for multiple impact events shows good agreement between measured acceleration, number of skipping events and distanced traveled. The experiment reveals a new mode of skipping, “water walking”, which is observed for relatively soft spheres impacting at low impact angles. The mode occurs when the sphere gains significant angular velocity over the first several impacts, causing the sphere to maintain a deformed, oblong shape. The behavior …
A Procedure For The Calculation Of The Perceived Loudness Of Sonic Booms, Christian R. Bolander, Douglas F. Hunsaker, Hao Shen, Forrest L. Carpenter
A Procedure For The Calculation Of The Perceived Loudness Of Sonic Booms, Christian R. Bolander, Douglas F. Hunsaker, Hao Shen, Forrest L. Carpenter
Mechanical and Aerospace Engineering Student Publications and Presentations
Implementing a method to calculate the human ear’s perceived loudness of a sonic boom requires consulting scattered literature with varying amounts of detail. This work describes a comprehensive implementation of Stevens’ Mark VII in Python, called PyLdB. References to literary works are included in enough detail so that the reader could use this work as a guide to implement the Mark VII algorithm. The details behind the mathematics of the Mark VII algorithm are included and PyLdB is used to calculate the perceived loudness of an example pressure signature. PyLdB is benchmarked against a widely used and validated code by …