|
A Preliminary Investigation on Implementation
of Oscillatory Flow (OF) in Mini-Channels
--Kirubanandan Shanmugam
The expectation for any configuration of chemical/biochemical reactor is the presence of efficient mixing to enhance heat and mass transfer as needed for the application of interest. In the past decade, Oscillatory Flow (OF) has been implemented in chemical reactors to increase the heat transfer and mass transfer in a process, while maintaining plug-flow behavior. This technology has not yet been extended to mini-fluidic devices, and is being explored as a novel approach for enhanced passive mixing at mini/micro scales. As a preliminary step in process intensification of OF technology, this work explores the fundamental working principles of operation and extension of conventional correlations applied to mini-fluidic scales. The theoretical calculations of energy dissipation versus mixing are compared to existing mini-fluidic mixers in literature, illustrating the need to develop novel mixing geometries that take advantage of the OF field. The preliminary experimental results are provided for an OF generator, intended for use in subsequent experiments exploring mini-fluidic mixers with OF technology. © 2016 IUP. All Rights Reserved.
Modeling and Structural Analysis of Boot Nozzle
and Insert Plate of a Pressure Vessel
--Venkata Ravi Ram Pinninti, Ramakrishna Bhamidipati
and TVK Bhanu Prakash
Pressure vessels and tanks are used extensively in the petrochemical industry for process and storage purposes. In the areas of large openings, as in the case of cargo hatch opening, stress concentration is likely to occur at the corners of the openings because of the sudden change in the sectional area of the deck plate. To ensure the integrity of the pressure vessel, a plate of higher thickness, compared to the adjacent plates, is inserted at the corners and such plates are referred to as insert plates. This is done to enable the corner plates to withstand higher levels of stress because of inevitable stress concentrations. The paper presents a real-world instance of involving a part of design done for a very large refinery expansion project in India. © 2016 IUP. All Rights Reserved.
Experimental and Finite Element Analysis of Bending
Strength of Asymmetric Involute Spur Gears
--Narayan S Dharashivkar, Vilas B Sondur and Krishnakumar D Joshi
The paper presents a method for investigating the bending stress at the critical section of ‘Asymmetric Involute Spur Gear’. Profiles of an asymmetric gear tooth on drive side and coast side have different pressure angles. The method ISO/TC- 60 has been used to theoretically calculate the bending stress at the critical section of this gear. The determination of the tooth form factor, stress concentration factor, critical section parameters and contact ratio have been accomplished for each set of gear. The gears with different pressure angles have been modeled by using CATIA V-5 R15 software to carry out FE analysis using ANSYS 14.5 software. A 3D photoelasticity method has been used to experimentally find out the stress at the critical section of symmetric involute spur gear and asymmetric involute spur gear. A comparative analysis between theoretical method, FE method and experimental method to determine bending strength of asymmetric involute spur gear has been carried out. The percentage increase in bending strength of the asymmetric gear has been estimated. The weight comparison between symmetric and asymmetric spur gear has been carried out for different combinations of pressure angle, module and number of teeth. A substantial weight reduction has been achieved by using asymmetric spur gear instead of symmetric spur gear. © 2016 IUP. All Rights Reserved.
Experimental, Analytical and Numerical Analyses
to Calculate Stress Intensity Factor on Circumferential
Notched Round Bar
--Chetan Kaduba Mahajan and Ganesh D Korwar
The Stress Intensity Factors (SIF) of surface notch on circular bar have been evaluated by singular element with detailed mesh on crack front and appropriating adjacent area. The attention is focused on a circular bar with notch surface crack under tension load. SIF are considered using the finite element method. For that purpose, a straight round bar under tension is investigated. It also addresses the related change of the equivalent notch angle of crack profile with respect to crack depth ratio. SIF of elliptical surface cracks in tensile round bars are calculated by using three-dimensional Finite Element Analysis (FEA) models with singular 20- node elements arranged around the crack tip. The graphic and the table review of SIF are also determined. The SIF are calculated for various dimensions of surface cracks. These results are used to determine an analytic form of the SIF that is necessary in crack growth analyses. Using the derived analytic formulae for the SIF based on the FEA, a crack growth analysis is carried out. © 2016 IUP. All Rights Reserved.
Some Considerations for the Design of Composite Armor
--Rahul Basu
Armor plating has been used primarily in static and surface-based (land and water) equipment. Aircraft usage has been restricted due to weight restrictions. This paper takes a look at the basic theory and parameters to derive those applicable to light weight armor for aircraft. The creation of new surfaces by internal fracture removes much of the impact energy during the transient stages. Hence, the continuum formula for composites requires modification to account for transients in moduli and area variations, as also for texture variations in various layers. Equations describing variation of various material parameters are examined to give insights into ways of strengthening the composite structure. © 2016 IUP. All Rights Reserved.
|
