Design of 1 :7 .645 scale LCA high speed air intake model

This report details the mechanical design aspects of the 1:7.645 scale LCA high speed air intake model. The model is intended to generate intake data in the transonic range 0.7 & 1.3 by Aeronautical Development Agency. The model has been designed for testing in the S2MA ONERA wind tunnel facilities. The 1:7.645 scale model is basically a composite model with metallic bulkheads/inserts and mainly consists of front fuselage, the wing, the canopy, interchangeable front duct modules, the rear portion of the CFRP duct, the main bulkhead, the heat exchanger duct, the sting, kulite rake, rear portion of the metallic duct including venturi, butterfly valve and diffuser. The kulite rake, the sting and the rear portion of the duct available with ONERA is made use of in the present model design. The steel bulkhead provides anchor support for the model in the tunnel through a flange mounted sting. The model has been designed to meet all the requirements of ONERA regarding model design and construction. For the design of the present model, the critical loads are scaled down from the load data of the 1:4.405 scale model. Structural analysis based on strength of materials approach has been carried out on the components of the model viz. forward fuselage, main bulkhead, air intake duct, and the splitter plate. FEN analysis has been carried out on the wing which is supposed to be the critical element of the model. The stress analysis shows that adequate margins of safety are available for all the components of the model

Evaluation of Educational Material for Low-Literacy Populations in India

During the COVID-19 pandemic, many children from limited-literacy communities in India did not receive information regarding COVID-19 safety due to the sudden shutdown of schools. Many parents from these communities could not afford virtual learning and lacked the ability to educate the children themselves. In July 2021, the research team developed comic, coloring, and activity books to provide children with fun, yet readable, educational materials. We consulted with teachers to simplify the language and understand the popularity of different cartoon characters. Between August 2021 and January 2022, our community health partners distributed the books to two age groups, ages 6–10 (n = 116, mean age 8.72) and 11–14 (n = 81, mean age 12.05). We conducted surveys with the children during and a week after distribution to assess any change in their knowledge about COVID-19 safety. The average age of children in this study was 10.09 (SD = 2.01) years. All resided in underresourced urban communities with low literacy rates and limited education. All questions were answered more correctly in the postsurvey, with the social distancing question having the greatest and most statistically significant increase (33.6%, p < 0.0001). The average increase in knowledge among children aged 6–10 (16.9%) was greater, though not statistically significantly so, than the average increase among children aged 11–14 (4.7%). These results indicate that child-friendly books can increase health education for children ages 6–14 in low-literacy populations. Additionally, the mechanism of the program is fit to be used in other low-resource populations globally

Application of photoclick chemistry for the synthesis of pyrazoles via 1,3‐dipolar cycloaddition between alkynes and nitrilimines generated in situ

The photochemical extrusion of gaseous nitrogen from 2,5-disubstituted tetrazoles to generate reactive nitrilimines in situ represents an efficient and attractive way to form dipoles that can be used to provide useful chemicals via 1,3-dipolar cycloadditions. The concept of “photoclick chemistry” already inspired numerous researchers, who exploited photochemical processes involving alkenes for the synthesis of adducts or the functionalization of biocompatible materials. The approach requires bioorthogonality, ease of access to the starting materials and operational simplicity. We report herein our investigations toward a photoclick reaction involving 2,5- disubstituted tetrazoles and alkynes as the dipolarophile for the synthesis of pyrazole derivatives. In addition to the numerous reports recently published on the synthesis of pyrazoles, we wish to add to the list a photochemical procedure that represents a mild and atom-economical alternative. Moreover, considering that such nitrilimines precursors can be accessed in one step from inexpensive and abundant starting materials and given the commercial availability of a broad spectrum of alkynes, we examined the scope of the photoclick reaction with respect to reactive partners, enabling the synthesis of a library of useful heteroaromatics

Mechanical design of 1:4.405 scale LCA high speed air intake Model

This report presents the mechanical design features, materials used and the structural design details of the 1:4.405 Scale LCA High Speed Air-intake Model. The model - design makes use of advanced composite materials and steel bulkheads/inserts. A steel bulkhead acts as support for the sting mounting of the model in the tunnel and also provides support points for mounting the front fuselage, duct, wing, rear fuselage frame and the rear fuselage cover. The model design allows necessary yaw angle capability, the required pitching motion, mass flow control through the duct, and variation of heat exchanger mass flow. Modular concept has been fully used in the, model design so as to obtain all the configurations of the model easily. Basic structural analysis making-use of strength materials approach was carried out for all the newly designed components, since the model makes use of many components of a model tested in an earlier campaign. Each component of the model is analysed to determine the working stress level under its critical tunnel operating condition

FEM design and analysis of HAL - Autoclave

Finite Element Structural Analysis of HAL Autoclave System and Components was carried out for the original design under all possible critical load combinations. It was noted that the original design was unsafe from both deformation and stress points of view. Certain design modifications were suggested. Each modification was critically evaluated using simple 1- and 2-dimensional finite element analysis. These modifications were incorporated in the autoclave design and a full-scale finite element analysis was carried out for the modified autoclave system. It was found that the modified system is SAFE from both deformation and stress points of view. MSC-XL is used for finite element modeling and for post-processing the results. MSC/NASTRAN is used for the finite element analysis. FEPACS is used for verification of the MSC/NASTRAN results where necessary

1:4.405 scale LCA High speed air-intake model: Revised analysis and design

As a follow up of the recommendations of the design review committee a few modifications were made in the structural design of the LCA wing. The important among them being the addition of three more bolts on the rear side of the port wing to strengthen, the wing attachments. Steel leading edge proposed in the original design was replaced by an aluminium alloy leading edge. A revised finite element analysis of the wing establishes that in general the stress levels are low over a large portion of the wing. The stress values in the wing bolts show that the bolts have adequate factor of safety. The splitter plate analysis results point to the adequate strength of them, and the natural frequency spectrum, shows that the fundamental frequency of the old model is much above the buzz frequency. The latter observation leads to they conclusion that the buzz noticed in the model is not due to any resonance phenomenon

Mechanical design of a caliper type brake test rig

This report covers the mechanical design aspects of a caliper type brake test rig which was designed to study the performance of high energy brake pad materials. The rig has been designed to generate kinetic energy of about 3450 m-kg to test a pair of brake pad specimens of 8.4 cm2 under different normal loads and rubbing speeds. Included in this report are the mechanical design philosophy as well as the general approach to the measurement of important test parameters. Proving tests conducted to study the performance of the rig are also reported

Mechanical design aspects of a large rotating arm serve controled filament winding machine

THe design presented in this report is a part of the development work carried out under the roject quot;Development of large filament wound reinforced plastic pressure vesselsquot;, sponsored by Aeronautics Research amp; Development Board.The filament winding machine chosen for the design study is of rotating arm type suitalble for producing fibre reinforced plastic shells of the diameter and 4. 2m length 0 The machine has been designed to produce polarlas well as hoop winding patterns. Moreover, helical patterns can also be obtained with the help of a data track programmer. The machine is driven hydronatically and employs closed loop servo controls for its operation. The machine utilities pre-imprognated material for winding FRP shells. Included in this reports are brief descriptions of the choice of main components of the machine,their salient design features, and their operating principles