Engineering Commons^™

Assessment Of Cooling And Heat Transfer Properties Of Quenchants With Matlab, Lemmy Meekisho, Rosa L. Simencio Otero, Jônatas M. Viscaino, D. Scott Mackenzie, George Totten, Lauralice C.F. Canale

Mechanical and Materials Engineering Faculty Publications and Presentations

There is ongoing interest for evaluating the potential of renewable base stocks, such as vegetable oils, to replace petroleum oils as metal quenchants. Perhaps the most critical part of this process is characterizing and comparing the cooling and heat transfer performance of potential quenchant candidates. In this work, cooling curves of two vegetable oils, palm oil and canola oil, were obtained along with a commercially available conventional and an accelerated petroleum quenchant using the so-called Tensi multiple thermocouple probe, with emphasis on the center probe emulating a small probe concept. The lumped-parameter approach was implemented in the MATLAB environment (Mathworks …

Quenchant Cooling Curves, Rewetting, And Surface Heat Flux Properties Of Vegetable Oils, Rosa L. Simencio Otero, Jônatas M. Viscaino, Jun Xu, Jianfeng Wu, George Totten, Lauralice C.F. Canale

Mechanical and Materials Engineering Faculty Publications and Presentations

Vegetable oils are currently used for biodegradable and renewable base stocks for quenchant formulation. However, there are relatively few references relating to their true equivalency, or lack thereof, comparative to the quenching performance of petroleum oil-based quenchant formulations. To obtain an overview of the variability vegetable oil quenching performance, the cooling curves and rewetting properties were determined, and the surface heat flux properties were calculated. The vegetable oils that were studied included canola, coconut, corn, cottonseed, palm, peanut, soybean, and sunflower oils. Cooling curves were obtained using the Tensi multiple-surface thermocouple 15 mm diameter by 45 mm cylindrical Inconel 600 …

First-Principles Study Of The Products Of Co2 Dissociation On Nickel-Based Alloys: Trends In Energetics With Alloying Element, Lynza H. Sprowl, Benjamin Adam, Julie D. Tucker, Líney Árnadóttir

Mechanical and Materials Engineering Faculty Publications and Presentations

Oxidation and corrosion of nickel and Ni-based alloys are a problem for many industrial applications, such as power plants that use supercritical CO2 as the working fluid. In supercritical CO2 environments, CO2 dissociates on the surface forming adsorbed CO and O, which can oxidize the surface. The adsorbed CO can further breakdown via direct CO dissociation or via the Boudouard reaction to form adsorbed C, which can in turn carburize the surface. Understanding how the adsorbed species interact with different Ni-based alloys can help guide the design of future alloys. The interactions of adsorbed O, C, and CO on the …

Evolution From Cooling Modeling To Cooling Engineering Of The Steel Quenching Process: A Technology Overview, Xinmin Luo, George Totten

Mechanical and Materials Engineering Faculty Publications and Presentations

The type of heat treatment process used is mainly determined by its cooling mode. Hardening is a metal heat treatment during which the most critical operation is cooling. Most quenchants used for steel hardening are vaporizable liquids, such as water, petroleum oils, emulsions, aqueous polymer solutions, or brines. Testing methodologies that include ISO 9950, Industrial Quenching Oils-determination of Cooling Characteristics-Nickel-alloy Probe Test Method, and ASTM Standards: D6200, Standard Test Method for Determination of Cooling Characteristics of Quench Oils by Cooling Curve Analysis, D6482, Standard Test Method for Determination of Cooling Characteristics of Aqueous Polymer Quenchants by Cooling Curve Analysis with …

New Era In Designing And Governing Cooling Intensity Of Liquid Quenchants To Decrease Distortion During Hardening Of Steel Parts, Nikolai I. Kobasko, Anatolii A. Moskalenko, P. N. Logvynenko, George E. Totten, Volodymyr V. Dobryvechir

Mechanical and Materials Engineering Faculty Publications and Presentations

It was proved in last decade that very intensive and uniform cooling eliminates quench crack formation and significantly decreases distortion of quenched steel parts as compared with their slow cooling in mineral oils. That opened a new era in design ing and governing cooling intensity of liquid quenchants for strengthening steel parts and decrease their distortion after quenching. The new approaches were developed by authors to provide accelerated and uniform cooling steel parts during quenching by creation on their surface thin insulating layers. For this purpose low concentration of water polymer solutions of inverse solubility are used as a quenchant. …

Mass Accretion And Ozone Reactivity Of Idealized Indoor Surfaces In Mechanically Or Naturally Ventilated Indoor Environments, Elliott T. Gall, Donghyun Rim

Mechanical and Materials Engineering Faculty Publications and Presentations

In indoor environments, accretion of mass to materials may provide sites for surface chemistry that differ from those of the original material. Since indoor surfaces are a major sink of oxidant gases, surface mass accretion may impact indoor O₃ chemistry. In this study, the effect of surface mass accretion on O₃ surface deposition was tested by deploying cleaned borosilicate glass plates in two types of indoor environments: a mechanically ventilated ( MV ) office and a naturally ventilated ( NV ) residence located in Singapore. In each environment, seven replicate glass plates and one field blank were deployed …

Three Speed 3d Printed Magnetic Gear, Robert J. Rutherford

Undergraduate Research & Mentoring Program

Power transmission is traditionally achieved with a mechanical gear. Mechanical gears require maintenance, cause vibration, and have no overload protection. Magnetic gears offer an innovative solution to these drawbacks as they do not require regular maintenance, have no need for lubrication, create very little acoustic noise, have built in overload protection and as a result of these advantages, have a longer lifetime of operation. This research focused upon the design, assembly and demonstration of the magnetic gear concept. The research used a solid works design, 3D printed ABS plastic housing, and use of neodymium magnets and ferromagnetic iron segments.

This …

Designing Model Experiments Around Harriet Tubman Middle School, Ryan Crist, Sarah Smith, Greg Sakradse, Ryan Scott

Undergraduate Research & Mentoring Program

Air quality is of concern in densely populated areas and especially near sources of inefficiently exhausted fossil fuel such as near the highway. Harriet Tubman middle school in North Portland, Oregon is situated alongside highway 5. Here, model experiments are designed and proposed to observe the instantaneous flow fields reflect modifications. LIDAR data was used to model the school and surrounding topography three-dimensionally in order to construct a model school and surrounding area from laser cut cardboard with a surface smoothed with paper mache. This model will be placed in the Portland State University wind tunnel; transport of mean and …

Ozone Removal Efficiency And Surface Analysis Of Green And White Roof Hvac Filters, Omed A. Abbass, David Sailor, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Heating, ventilation, and air-conditioning ( HVAC ) system filters from a commercial building were tested for their ability to remove ozone from intake air. Filters were taken from rooftop HVAC systems installed for two months: one located on a white membrane roof and the other on a vegetated green roof. One new, unused filter sample was tested as a reference. Samples from these filters were exposed to ozonated air streams at 40 and 120 ppb and relative humidity levels of 30% and 70%. Filter surfaces were analyzed with a scanning electron microscope to observe the structure and composition of the …

Assessing Spacing Impact On Coherent Features In A Wind Turbine Array Boundary Layer, Naseem Ali, Nicholas Hamilton, Dominic Delucia, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

As wind farms become larger, the spacing between turbines becomes a significant design consideration that can impose serious economic constraints. To investigate the turbulent flow structures in a 4 x 3 Cartesian wind turbine array boundary layer (WTABL), a wind tunnel experiment was carried out parameterizing the streamwise and spanwise wind turbine spacing. Four cases are chosen spacing turbines by 6 or 3D in the streamwise direction, and 3 or 1:5D in the spanwise direction, where D = 12 cm is the rotor diameter. Data are obtained experimentally using stereo particle image velocimetry. Mean streamwise velocity showed maximum …

Terahertz Imaging Of Thin Film Layers With Matched Field Processing, Scott Schecklman, Lisa M. Zurk

Electrical and Computer Engineering Faculty Publications and Presentations

Terahertz (THz) time of flight (TOF) tomography systems offer a new measurement modality for non-destructive evaluation (NDE) of the subsurface layers of protective coatings and/or laminated composite materials for industrial, security and biomedical applications. However, for thin film samples, the time-of-flight within a layer is less than the duration of the THz pulse and consequently there is insufficient range resolution for NDE of the sample under test. In this paper, matched field processing (MFP) techniques are applied to thickness estimation in THz TOF tomography applications, and these methods are demonstrated by using measured THz spectra to estimate the the thicknesses …