Mechanical Engineering Commons^™

Prediction Of Crack Growth Rate And Load Interaction Effects Using Damage Accumulation Model, Virender Goswami

Masters Theses

In damage tolerant designs, it is important to know the crack growth behavior of a material, so that sudden failure of a component can be avoided by determining a safe life. There are numerous models available to predict the crack growth rate. Among them the "crack closure model" is most often used for predicting the crack growth rate for different R-ratios and load interaction effects. However recently, the crack closure model has come under criticism by many authors to be flawed and overrated owing to its inherent drawbacks.

Therefore, a mathematical model for the fatigue crack propagation based on damage …

Analysis Of Combustion Chamber Design Variables In Planetary Rotary Engine, Sathyanarayanan Arumugam

Masters Theses

This research entails examining the Hopkins Rotor Mechanism (HRM) for the perspective of commercial viability. Factors that were studied herein include basic operating characteristics, combustion effects, dimensional changes and behaviors unique to the HRM that may impose limits to commercial viability were also examined.

To compare specific characteristics of the HRM engine, in a comparable four-stroke mode, hypothetical 200, 400 and 600 cubic centimeter (cc) single cylinder reciprocating engines, each with compression ratio of 10, 15 and 20 were used as a basis for comparison. For similar outputs this resulted in the use of a 100, 200, 300 cc HRM …

Comparing Refractory Coatings On Shell Sand Utilizing Elevated Temperature And Collapsibility Testing, Suet Fong Cheah

Masters Theses

This research study examines the effects of refractory coatings on a shell sand using laboratory testing equipment as opposed to the more laborious and time consuming processes of molding, melting, filling, shakeout, and obtaining dimensions of actual castings. As of today, there have not been any such laboratory test methods. This research project focused on quantifying distortion, mass change, and impact strength found in refractory coated shell sand. The equipment used was the thermal distortion tester (TDT) and a modified impact tester. The thermal distortion curves (TDC), mass change, and impact strength are provided and compared for all systems studied. …

Subcooled Pool Boiling Heat Transfer Using R113 On Flat Surface, Kamleshkumar J. Suthar

Masters Theses

Pool boiling experiment was conducted to investigate the effect of subcooling on boiling of R-113 using 25mm effective dia. flat surface copper heater. Pool boiling heat transfer measurements were taken for wide temperature range of 5 - 39^o C subcooling and investigated thoroughly. Variation in value of wall superheat of incipience boiling, from 27 to 34^o C and 7 to 11^o C temperature excursion observed. Noticeable effect of subcooling on boiling heat transfer is observed. Degree of subcooling was maintained constant by regulating pressure and keeping constant fluid temperature for each test run. Tests were conducted by …

Using Stiffeners For Improved Geometric Fidelity Of Flexible Elements, Ankit Kapoor

Masters Theses

Flexible hoses play an important role in safe operation of a transportation vehicle in automotive and aerospace field. Due to lack of accurate and efficient modeling techniques for such flexible elements with large deformation, most Computer Aided Engineering system do not address the problem in their solution methods.

In this thesis a method is presented to improve the geometric fidelity of flexible element models by using off-axis bi-linear stiffeners (spring) into a discrete linear beam model. Resulting deflection of a hose were compared with the digital scans of an actual deflection of the hose. Though the method is computationally expensive, …

Methodology To Predict The Instantaneous Friction Work In Non-Conventional Internal Combustion Engines, Ravishankar Thangavelu

Masters Theses

Non-Conventional Internal Combustion Engine (NCICE) may utilize a variety of contact surface shapes, where both sliding and rolling losses occur. This study develops techniques that allow the user to define the type of forces and the characteristics of the friction type to predict the instantaneous and over all friction work in a NCICE under user defined operating conditions. The characteristics include inertial effects, contour and surface effects, resulting contact surface changes and film thickness changes as a result of contact surface.