We derive a nonlinear fuel optimal attitude control system (ACS) that drives the final state to the desired state according to a cost function that weights the final state angular error relative to the angular rate error. Control is achieved by allowing the pulsewidth-modulated (PWM) commands to begin and end anywhere within a control cycle, achieving a pulse width pulse time (PWPT) control. We...

BACKGROUND Infrastructure compatible hydrocarbon biofuel proposed to qualify as renewable transportation fuel under the U.S. Energy Independence and Security Act of 2007 and Renewable Fuel Standard (RFS2) is evaluated. The process uses a hybrid poplar feedstock, which undergoes dilute acid pretreatment and enzymatic hydrolysis. Sugars are fermented to acetic acid, which undergoes conversion to ...

Bio-jet fuel has already been used in commercial flights to decarbonize the aviation transportation sector. However, widespread use of bio-jet is still a challenge partly due high production costs. In particular, from lipids requires temperatures and includes multiple reaction units, i.e., hydrodeoxygenation hydrocracking, increasing operation The integration these processes one pot was attempt...

Accidental release scenarios such as flammable gas leaks or ruptures of pipes and pressurised process-equipment normally originate high velocity jets which, if ignited, give rise to jet fires. Although the direct effects of jet fires are considered to be relatively smaller than that associated to other types of fires, they are characterized by high heat fluxes and, especially if there is flame ...

For industrial applications, we propose a concept of clean and efficient combustion through burning syngas on an impinging burner. We performed experimental measurements of particle image velocimetry, OH radical (OH*) chemiluminescence, flame temperature, and CO emission to examine the fuel mixing and reaction of premixed impinging flames of CH4/syngas/air with H2/CO in varied proportions. The ...

The effects of fuel and air stream dilution (ASD) with carbon dioxide on the suppression of normal and microgravity laminar methane–air partially premixed coflow jet flames were experimentally and numerically investigated. Experiments were conducted both in our normal-gravity laboratory and at the NASA Glenn Research Center 2.2 s drop tower. Measurements included flame topology and liftoff heig...

The use of liquid fuels necessitates methods to assess the quality and suitability of these fuels for their intended use. Traditionally, this is performed through a series of chemical and physical tests. However, in some operational situations, streamlined methods to reliably evaluate fuel quality would offer distinct advantages. The Naval Research Laboratory has been engaged in a research prog...

Emissions from aircraft engines represent a highly complex and important issue, which is related to the risk to human health. Particles emitted in urban areas and in the vicinity of airports affect air quality and have a particularly negative impact on airport workers. The development of measurement techniques and the methodology for evaluating exhaust emissions have allowed for the elaboration...