Design and development of large wind turbine blades is a challenging job due to a variety of requirements related to economic, logistic, manufacturing, and technical constraints. Among the technical requirements, shape optimization is an important part in the design of wind turbine blades. New-Age Flatback turbine blade is a recent development, and it consists of a blunt trailing edge?which generates a larger moment of inertia?and has an aerodynamic performance, a little bit better than the common profiles. The paper, ?Modeling and Simulation of a 3 MW Wind Turbine Blade for Determination and Analysis of Flow Characteristics?, by Amool A Raina, Saeed Farokhi and Kyle Wetzel, presents a comprehensive 3D analysis of a rotating wind turbine to predict the aerodynamic behavior for a large rotor blade structure. The authors have subjected the blade model with length of 56 m, maximum chord section of 4.2 m and prebend of 1.2 m (added primarily for structural reasons) to understand the flow characteristics in the hub/transition region of the blade. The authors have presented a full-scale analysis of large wind turbine blades to solve the fluid dynamic problem with the help of a finite-volume, Reynolds-Averaged Navier?Stokes (RANS) solver. A comparison of the results obtained from RANS with those obtained from Blade Element Momentum (BEM)-based methods shows that RANS simulation resulted in a higher energy capture as compared to predictions obtained from BEM.

Laser-based machining methods like laser cutting, welding, cladding, engraving, surface treatment and drilling have wide applications in machining various materials. Laser engraving finds enormous applications in every industry ranging from automotive to aerospace. Due to the increasing demand for rapid prototyping and 3D printing technologies, it has become quite essential for industries to look for better techniques and design, without compromising on quality standards. In the present-day scenario, industrial equipment is becoming compact, miniaturized and smarter. The paper, ?Design and Fabrication of Laser Engraving Machine?, by Rahul Mehra, Sachin Mohal and B Lonia, presents details of a low-cost rapid prototype laser engraving machine. The 3D modeling and simulation of this machine is done using CREO 2.0 software. A 15 W diode laser is used to engrave various materials. The authors have validated the machine by performing dimensional and dependency tests. Pilot experimentation has been carried out on GFRP composites. Undoubtedly, the indigenously developed machine has cost-effectiveness and better performance in comparison to currently available laser engraving machines.

Ever increasing prices of petroleum and coal have thrown challenges for efficient ways of generating energy. Heat exchanger as a device of energy utilization is widely accepted and applied to chemical process, petroleum, power, refrigeration, food processing, etc. Entransy effectiveness is a measure of the irreversibility of the heat transfer process in the heat exchanger. The term ?entransy? is a recently coined one, used to define the efficiencies of heat transfer processes and to optimize heat transfer processes. More dissipation of entransy implies higher degree of irreversibility in heat transfer process. The paper, ?The Effect of Optimum Entransy Dissipation Number on the Performance of Heat Exchanger?, by Roopesh Tiwari and Govind Maheshwari, presents a new concept of optimum entransy dissipation number which is defined as the ratio of actual entransy dissipation to the optimum entransy dissipation. The optimum entransy dissipation number is found to decrease for both parallel flow and counter flow, with the increase in the Number of Transfer Units (NTU) for a given heat capacity rate ratio. The authors have found that the counter flow arrangement yields a better result, as compared to parallel flow arrangement. Further, based on a comparison of the variation of optimum entransy dissipation number with the variation of entransy dissipation number, the authors have concluded that optimum entransy dissipation number can be used to evaluate the heat exchanger performance.

The next paper, ?Perturbation Analysis of Glassy Alloy Film Formation?, by Rahul Basu, presents a coupled set of equations describing heat and mass transfer during phase transformation, incorporating surface convective effects. A relation is found for the effect of the glass transition temperature versus the boundary layer thickness for several alloys in various groups of the periodic table. Physically, a boundary layer is found to exist between liquid and solid by foundry technologists, which is referred to as ?mushy zone?. The author has obtained the rate of transformation between the liquid and solid phase by solving the Moving Boundary Problem (MBP).

The last paper, ?Exergy Analysis of Gautami Combined Cycle Power Plant, India: A Case Study?, by Venkata Ravi Ram Pinninti, T V K Bhanuprakash, Ramamurthy Dwivedula and Rama Jonnada, presents a case of Gautami combined cycle power plant, Andhra Pradesh, India. Using theoretical thermodynamic analysis and actual real plant operational data, the loss due to exergy in different cycle components is calculated. The case also presents the influence of critical parameters like compressor discharge pressure and gas turbine inlet temperature on exergy destruction in different combined cycle components.