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Second law analyses of both spark-ignition and diesel engines are presented using two-zone models. The analyses include descriptions of the evaluation of the various terms in the availability balance. Chemical and thermomechanical availability are separated using a definition which allows the portion of the fuel availability that can be extracted by a combustion engine to be distinguished from that which requires interaction with the reference environment. The chemical availability must be calculated correctly in order to obtain an availability balance. The diesel model includes a parameter that allows the effect of fuel-air mixing rates to be simulated. The analyses for the spark-ignition and diesel models are applied in a parametric study of the effects of equivalence ratio, fuel-air mixing, residual fraction and combustion duration on the chemical and thermomechanical availability and the irreversibility.

This paper describes the development of a thin-film optical sensor for measuring pH. The indicator behaves as a polyprotic acid with differing optical properties in each of its chemical forms. Together, these properties facilitate the development of an internally calibrated sensor by calculating the ratios of the absorption maximas for each form of the indicator. The covalent immobilization procedure developed demonstrated long term stability of 4 months without recalibration.

This paper presents a review of our current experimental and theoretical understanding of icing feathers and the role that they play in the formation of ice accretions. It covers the following areas: a short review of past research work related to icing feathers; a discussion of the physical characteristics and terminology used in describing icing feathers; the presence of feathers on ice accretions formed in unswept airfoils, especially at SLD conditions; the role that icing feathers play in the formation of ice accretion shapes on swept wings; the formation of icing feathers from roughness elements; theoretical considerations regarding feather formation, feather interaction to form complex icing structures, the role of film dynamics in the formation of roughness elements and the formation of feathers. Hypotheses related to feather formation and feather growth are discussed.

In this paper, we present a framework for the robot to learn how to place objects to a workpiece by learning from humans in smart manufacturing. In the proposed framework, the rational scene dictionary (RSD) corresponding to the keyframes of task (KFT) are used to identify the general object-action-location relationships. The Generalized Voronoi Diagrams (GVD) based contour is used to determine the relative position and orientation between the object and the corresponding workpiece at the final state. In the learning phase, we keep tracking the image segments in the human demonstration. For the moment when a spatial relation of some segments are changed in a discontinuous way, the state changes are recorded by the RSD. KFT is abstracted after traversing and searching in RSD, while the relative position and orientation of the object and the corresponding mount are presented by GVD-based contours for the keyframes.

Recently developed dielectric barrier discharge (DBD) plasma-based anti-icing systems have shown great potential for aircraft icing mitigation. In the present study, the ice accretion experiments were performed on to evaluate the effects of different layouts of DBD plasma actuators on their anti-/de-icing performances for aircraft icing mitigations. An array of DBD plasma actuators were designed and embedded on the surface of a NACA0012 airfoil/wing model in different layout configurations (i.e., different alignment directions of the plasm actuators (e.g., spanwise vs. streamwise), width of the exposed electrodes and the gap between the electrodes) for the experimental study. The experimental study was carried out in the Icing Research Tunnel available at Iowa State University (i.e., ISUIRT).

An experimental study was conducted to investigate the dynamic ice accretion processes on bridge cables with different surface modifications (i.e., 1. Standard plain, 2. Pattern-indented surface, and 3. helical fillets). The icing experiments were performed in the unique Icing Research Tunnel available at Iowa State University (i.e., ISU-IRT). In order to reveal the transient ice accretion processes and the associated aerodynamic loadings on the different cable models under the different icing conditions (i.e., rime vs. glaze), while a high-speed imaging system was used to capture the transient details of the surface water transport and ice accretion over the cable surfaces, a high-accuracy dual-transducer force measurement system was also utilized to measure the aerodynamic loadings acting on the ice accreting cable models.

In the present study, an experimental investigation was conducted to characterize a hot-air-based anti-/de-icing system for the icing protection of aero-engine inlet guide vanes(IGVs). The experimental study was conducted in a unique icing research tunnel available at Iowa State University (i.e., ISU-IRT). A hollowed IGV model embedded with U-shaped hot-air flowing conduit was designed and manufactured for the experimental investigations. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion or anti-/de-icing process over the surface of the IGV model for the test cases without and with the hot-air supply system being turned on, the corresponding surface temperature distributions on the IGV model were measured quantitatively by using a row of embedded thermocouples.

Wind turbine icing represents the most significant threat to the integrity of wind turbines in cold weather. Ice formation on wind turbine blades was found to cause significant aerodynamic performance degradation, resulting in a substantial drop in energy production. Recently developed Dielectric barrier discharge (DBD) plasma-based anti-/de-icing systems showed very promising effects for aircraft icing mitigation. In this present study, DBD plasma-based anti-/de-icing systems were employed for wind turbine icing mitigation. First, a comprehensive parametric study is conducted to investigate the effects of various DBD plasma actuation parameters on its thermodynamic characteristics. An infrared (IR) thermal imaging system is used to quantitatively measure the temperature distributions over the test plate under various test conditions.

The electro-thermal method is most commonly used for wind turbine anti-/de-icing. The upmost drawback of such systems is the high power consumption. In the present study, we proposed to use a durable slippery liquid-infused porous surface (SLIPS) to effectively reduce the power requirement of the heating element during the anti-/de-icing process. The explorative study was conducted in the Icing Research Tunnel at Iowa State University (ISU-IRT) with a DU91-W2-250 wind turbine blade model exposed under severe icing conditions. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion process, an infrared (IR) thermal imaging system was also utilized to achieve the simultaneous surface temperature measurements over the test model.