Overview
Josiah Knight, Associate Professor of Mechanical Engineering, is Co-Director of the Energy and Environment Certificate, a program that prepares students to confront complex problems in providing safe, clean, reliable and affordable energy. The curriculum brings together students from arts and sciences as well as engineering in a series of courses spanning natural science, social science and technology, culminating in a capstone course in which multidisciplinary teams design, build, test and evaluate energy system prototypes. In the process, students learn to communicate across a spectrum of backgrounds and interests, as they must do to address energy problems in the larger world.
Knight's current research interests are in solar thermal energy and alternate propulsion methods for ground transportation. Solar thermal energy, in addition to direct uses for space, water and industrial heating, has been shown to be an efficient means of electricity generation. Much progress has been made in recent years on fault-tolerant solar thermal collectors, and integration of such systems with distributed power generation is a promising path toward low-carbon electricity.
Alternatives to the gasoline and diesel internal combustion engine have potential to expand the range of fuels that can be efficiently used for transportation and stationary power. A major issue in the development of biofuels for ICEs is that much of the heating value of the biomass is consumed in transforming the solids to liquid fuels. Burning solid biomass directly delivers greater net energy, but must be done in external combustion. Activity in this area is presently focused on optimizing performance of external combustion engines by using adaptive intake and exhaust porting and closed-loop valve control. The area is rich in both applied and basic questions that couple thermodynamics and electro-mechanical dynamics in nonlinear regimes.
Current Appointments & Affiliations
Recent Publications
Predicting critical speeds in various rotordynamics problems
Journal Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science · November 1, 2017 Rotating shafts often experience undesirable large-amplitude whirling oscillations associated with resonance at critical speeds. This paper further develops a nondestructive technique in which measured information about the growing nature of the response i ... Full text CitePredicting Critical Speeds in Rotordynamics: A New Method
Conference Journal of Physics: Conference Series · October 3, 2016 In rotordynamics, it is often important to be able to predict critical speeds. The passage through resonance is generally difficult to model. Rotating shafts with a disk are analyzed in this study, and experiments are conducted with one and two disks on a ... Full text CiteA New Method for Predicting Critical Speeds in Rotordynamics
Journal Article Journal of Engineering for Gas Turbines and Power · February 1, 2016 The prediction of critical speeds of a rotating shaft is a crucial issue in a variety of industrial applications ranging from turbomachinery to disk storage systems. The modeling and analysis of rotordynamic systems is subject to a number of complications, ... Full text CiteRecent Grants
Team Projects in Energy Design
ResearchPrincipal Investigator · Awarded by North Carolina State University · 2015 - 2019NASA Space Solar Thermal Power
ResearchPrincipal Investigator · Awarded by Space Grant · 2010 - 2015Travel in Support of Activities as President of the Society of Triboogists and Lubrication Engineers
Institutional SupportPrincipal Investigator · Awarded by Lord Foundation of North Carolina · 2002 - 2005View All Grants