Stickybot is a bioinspired robot that climbs smooth vertical surfaces such as glass, plastic, and ceramic tile at 4 cm/s. The robot employs several design principles adapted from the gecko including a hierarchy of compliant structures, directional adhesion, and control of tangential contact forces to achieve control of adhesion. We describe the design and fabrication methods used to create underactuated, multimaterial structures that conform to surfaces over a range of length scales from centimeters to micrometers. At the finest scale, the undersides of Stickybot's toes are covered with arrays of small, angled polymer stalks. Like the directional adhesive structures used by geckos, they readily adhere when pulled tangentially from the tips of the toes toward the ankles; when pulled in the opposite direction, they release. Working in combination with the compliant structures and directional adhesion is a force control strategy that balances forces among the feet and promotes smooth attachment and detachment of the toes.

/pdf/smooth-vertical-surface-climbing-with-directional-adhesion-zb2xusy7bv.pdf

Smooth Vertical Surface Climbing With Directional Adhesion

Wind energy is the fastest growing alternate source of energy in the world since its purely economic potential is complemented by its great positive environmental impact. The wind turbine, whether it may be a Horizontal-Axis Wind Turbine (HAWT) or a Vertical-Axis Wind Turbine (VAWT), offers a practical way to convert the wind energy into electrical or mechanical energy. Although this book focuses on the aerodynamic design and performance of VAWTs based on the Darrieus concept, it also discusses the comparison between HAWTs and VAWTs, future trends in design and the inherent socio-economic and environmental friendly aspects of wind energy as an alternate source of energy.

Wind turbine design with emphasis on Darrieus concept Ion Paraschivoiu

The Darrieus wind turbine: Proposal for a new performance prediction model based on CFD

This paper presents an integrated, systems-level view of several novel design and control features associated with the biologically inspired, hexapedal, RiSE (Robots in Scansorial Environments) robot. RiSE is the first legged machine capable of locomotion on both the ground and a variety of vertical building surfaces including brick, stucco, and crushed stone at speeds up to 4 cm-s, quietly and without the use of suction, magnets, or adhesives. It achieves these capabilities through a combination of bioinspired and traditional design methods. This paper describes the design process and specifically addresses body morphology, hierarchical compliance in the legs and feet, and sensing and control systems that enable robust and reliable climbing on difficult surfaces. Experimental results illustrate the effects of various behaviors on climbing performance and demonstrate the robot's ability to climb reliably for long distances. © 2008 Wiley Periodicals, Inc.

/pdf/biologically-inspired-climbing-with-a-hexapedal-robot-4nsm4rjfsn.pdf

Biologically inspired climbing with a hexapedal robot

In this paper, along with the progress of modern wind energy technology, the trends of wind energy technology and potential challenges have been studied thoroughly. It is estimated that within the next 2–3 decades, the Vertical Axis Wind Turbine (VAWT) can dominate the wind-energy technology. The VAWT requires less land space and using the same space; it is capable of producing more wind energy than that of its counterpart. By implying the Fish Schooling Concept effectively and successfully, it is possible to advance the wind-energy technology more. In the last 3–4 decades, the wind turbine capacity has been increased around 30–40 times. With the increase of wind energy capacity, the demand of the energy storage system has been increased significantly. Along with the many energy storage systems, fuel cells and batteries are the two most promising devices to meet the demand in RE systems. The wind-energy technology is established itself but not yet fully mature and hence there are many areas where improvements are required to reduce the cost of wind energy.

http://iran-tarjome.persiangig.com/other/1-s2.0-S1364032113000312-main.pdf

Progress and recent trends of wind energy technology

CFD modeling of a ducted Savonius wind turbine for the evaluation of the blockage effects on rotor performance

Determining the best geometric parameters for the blade of a wind turbine is critical for maximizing energy production. This paper considers how to determine the laws which govern twist to maximize electrical energy output for a rotor with two blades, with a 10 m diameter, in a given wind site.Optimum twist was obtained by applying the ‘blade element momentum theory’. Then two different blade design methods were compared. The first, based on maximizing the power coefficient (at the average wind velocity, assuming an attack angle which maximizes the ratio of lift and drag coefficients); the second, based on maximizing the annual energy production for the turbine object of this study, in a given wind site.

Optimal wind turbine design to maximize energy production

Several models for the evaluation of Gross Heat Release from the internel combustion engine (ICE) are 
often used in literature. One of these is the First Law - Single Zone model (FL-SZM), derived from the First Law of Thermodynamics. This model presents a twice advantage: first it describes with accuracy the physic of the phenomenon (charge heat release during the combustion stroke and heat exchange between gas and cylinder wall); second it has a great simplicity in the mathematical formulation. The evaluation of Heat Release with the FL-SZM is based on pressure experimental measurements inside the cylinder. and on the assumption of several parameters as the specific heat ratio. wall temperature. polytropic exponent for the motored cycle evaluation. and many others. In this paper the influence of gases thermodynamic properties on Gross Heat Release has been esteemed. In particular the influence of an appropriate equation for k= k(T) (specific heat ratio vs. temperature) which descrihes the variations of gases thermodynamic properties with the mean temperature inside the cylinder has heen evaluated. This equation has been calculated by new V order Logarithmic Polynomials (VoLP). fitting experimental gases properties through the least square methods.

Ice gross heat release strongly influenced by specific heat ratio values

On the Possibility to Run an Internal Combustion Engine on Acetylene and Alcohol

In this paper the authors describe a design and optimization process of micro HAWTs using a numerical and experimental approach. An in-house 1D BEM model was used to obtain a first geometrical draft. It allowed to quickly optimize blade geometry to maximize energy production as well. As these models are quite sensitive to airfoil coefficients, above all at low Reynolds numbers, an accurate 3D CFD model was developed to support and validate the 1D BEM design, analyzing and fixing the discrepancies between model output. The 3D CFD model was developed and optimized using ANSYS Fluent solver and a RANS transition turbulence model. This allowed to correctly reproduce the transition and stall phenomena that characterize the aerodynamic behavior of micro wind turbines, solving the issues related to low Reynolds flows. The procedure was completed, thus building two micro HAWTs with different scales, testing them in the subsonic wind tunnel of the University of Catania. Wind tunnel features, experimental set-up and testing procedures are presented in the paper. Through the comparison of numerical CFD and experimental test results, a good compatibility was found. This allowed the authors to analyze and compare numerical calculation results and verify blockage effects on the prototypes as well.

/pdf/numerical-and-experimental-analysis-of-micro-hawts-designed-35yk2bqfpv.pdf

Michele Messina

Papers

CFD modeling of a ducted Savonius wind turbine for the evaluation of the blockage effects on rotor performance

Optimal wind turbine design to maximize energy production

Ice gross heat release strongly influenced by specific heat ratio values

On the Possibility to Run an Internal Combustion Engine on Acetylene and Alcohol

Numerical and experimental analysis of micro HAWTs designed for wind tunnel applications