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This paper presents the dynamic responses of sandwich beams with 3D printed thermoplastic composite face sheets and multi-walled carbon nanotubes reinforced magnetorheological elastomer (MWCNT-MR elastomer) cores under non-uniform magnetic fields. A higher-order beam theory (HoBT) is employed to express the beam‘s displacement field. The governing equations of the 3D printed thermoplastic sandwich beam are derived using Lagrange‘s principle and discretized by the finite element method. The validity of the present method is confirmed through comparison with the results available in the literature. The stiffness and damping characteristics of the 3D printed thermoplastic sandwich beam are investigated in relation to support conditions, non-homogeneous magnetic flux, and core-face sheet thickness ratio.

The presence of a wide range of high- and low-resolution devices renders the images to experience changes in respect to aspect ratio and size for better adaptability. This paper proposes a novel and effective technique that vanquishes the problems encountered in the conventional seam carving method. To achieve minimum distortion in salient objects of the image, the proposed technique restricts intersection or overlapping of multiple seams in the horizontal and vertical direction and bypasses them to the neighboring low energy pixel. The proposed technique hinders the pixel selection from a single row or column beyond the defined threshold so as to save the image information and reduce distortion at a single location. To justify the effectiveness of the proposed technique, results have been presented in comparison with the five state-of-the-art image retargeting techniques. Compared with the conventional techniques, this technique shows remarkable results in terms of low distortion percentage. The proposed technique also produces excellent results for shrinkage and enlargement of a single image multiple times.

Flow visualization is the direct observation of fluid flow. Moving fluids form complex patterns and understanding and visualizing those patterns is an important aspect in aerospace industry. The previously existing research and results were taken into consideration for design parameters and calculation for dimensions of various parts of the wind tunnel. Design calculations allow wind velocities in the range of 1-3 m/s at the test section. The design includes a rectangular test section of 0.06m x 0.30m cross-section for accommodation of test object of width 0.06m. The design was made in SolidWorks and was fabricated with basic materials like plywood and acrylic sheets. PC cabinet fans were used for flow circulation. Liquid wax is utilized for the purpose of smoke generation and rubber and PVC pipes were utilized for smoke containment and delivery system. Profiles that were used for testing included cylinder, sphere, cuboid, NACA airfoils and flat plate.

Modifications achieved in the ignition delay time of shellac-based pyrotechnic igniter using different additives of varying particle size are observed and compared. 40 different pyrotechnic compositions were prepared using five additives i.e. aluminium, magnesium, red iron oxide, naphthalene and activated carbon. Four particle sizes i.e.

The paper presents the exhaustive literature review carried out for the design and analysis of MEMS based microthruster. Nowadays, Microthrusters are the latest technology used for the satellite application such as attitude control, orbital adjustment etc. The paper tried to discuss about its overall design, ignition system, propellant combination and the flow analysis. The authors have tried to summarize the contributions of various researchers in the field of MEMS based microthruster. The paper discusses in detail about the studies relating to design and analysis of the microthruster and its trade-offs. This study was aimed to enhance the knowledge by concluding various literatures and finding their research gaps. These gaps have been dealt effectively by providing probable discussions. The computational work includes the flow analysis of the nozzle which aims to achieve better results in all dimensions. The aim of this review was to summarize the recent progression as well as implementation of the microthruster to identify some challenging issues that need to be solved for future research. These challenges were deciphered using the recommendations based on the results of computational work and discussing the review of literatures

In this present work, the effect of hole shapes, orientation and hole arrangements on film cooling effectiveness has been carried out. For this work a flat plate has been considered for the computational model. Computational analysis of film cooling effectiveness using different hole shapes with no streamwise inclination has been carried out. Initially, the model with an inclination of 30° has been verified with the experimental data. The validation results are well in agreement with the results taken from literature. Five different hole shapes viz. Cylindrical, Elliptic, Triangular, Semi-Cylindrical and Semi-Elliptic have been compared and validated over a wide range of blowing ratios. The blowing ratios ranged from 0.67 to 1.67. Later, orientation of holes have also been varied along with the number of rows and hole arrangements in rows. The performance of film cooling scheme has been given in terms of centerline and laterally averaged adiabatic effectiveness. Semi-elliptic hole utilizes half of the mass flow as in other hole shapes and gives nominal values of effectiveness. The triangular hole geometry shows higher values of effectiveness than other hole geometries. But when compared on the basis of effectiveness and coolant mass consumption, Semi-elliptic hole came out to give best results.

This study deals with the film cooling enhancement in a combustion chamber by the use of rectangular winglet vortex generators (VGs). Rectangular winglet pair (RWP) in both the common-flow up and the common-flow down configuration is installed upstream of a coolant injection hole on the lower chamber wall. A three-dimensional numerical approach with complete solution of Navier–Stokes (NS) equations closed by the k–ɛ turbulence model is used for analyzing the effect of VG installation on film cooling effectiveness enhancement. The effect of RWP orientation is investigated to deduce the best configuration which is then optimized in terms of its geometrical parameters including its upstream distance from the hole and the angle it makes with the incoming flow. Results obtained show that a RWP located upstream of the coolant hole in common-flow down configuration gives the best effectiveness enhancement with certain other geometrical parameters specified. A novel “mushroom” adiabatic distribution scheme for film cooling effectiveness and temperature has been discussed in the paper. This characteristic scheme is developed as a result of RWPs' vortices interaction with the coolant inlet jet and the hot mainstream flow. A detailed discussion of the mechanisms and the flow field properties underlying the effectiveness enhancement and other phenomenon observed has also been presented in the paper.

The paper presents a novel study on film cooling effectiveness of a 3D flat plate with a multihole arrangement of mixed hole shapes. The film cooling arrangement consists of two rows of coolant holes, organized in a staggered pattern with an L/D (length to diameter ratio) of 10. The two rows consist of varied combinations of triangular and semi-elliptic shaped holes for the enhancement of film-cooling effectiveness. The results were obtained for a coolant to mainstream temperature ratio of 0.5 and a blowing ratio of 1.0. The computed flow temperature fields are presented in addition to the local two-dimensional streamwise and spanwise distribution of film cooling effectiveness. Validation of the results obtained from the turbulence model has been done with the experimental data of centerline film cooling effectiveness downstream of the cooling holes available in the open literature. The results showed the rapid merging of coolant jets emerging from front row of multiholes with the secondary staggered row of mixed holes. Due to the mainstream–coolant jet interaction, the strength of the counter rotating vortex pair was mitigated in the downstream region for certain arrangement of mixed hole shapes. The optimal hole combination with maximum overall effectiveness has been deduced from this study. The best configuration (M.R. VI) not only favored for the developed film, but also enhanced the averaged film cooling effectiveness to a large extent.

This paper presents computational analysis of centerline film cooling effectiveness using Navier-Stokes equation solver. Film cooling effectiveness has been varied along the downstream of cooling holes. The computational model has been validated with benchmark experimental literature. Computational study compares film cooling effectiveness over various blowing ratios (M) and various hole shapes. The k-ω shear stress transport model of FLUENT software has been used for the computational analysis. The hole geometry and blowing ratios have important effects on film cooling effectiveness. Computational results reveal that film cooling effectiveness increases with increase in blowing ratio whereas effectiveness decreases due to intermixing of coolant and mainstream flow and due to coolant jet lift off. The best results were obtained for fan-shaped hole with M=1.00. While for lower blowing ratio, coolant is unable to spread over a longer distance downstream of cooling holes.

Film cooling is employed for effective cooling in nozzles and combustion chambers using a spray of coolant fluid in the mainstream flow to cool the body. Experimental analysis was performed elaborately in the past years to get an exact analysis of film cooling effectiveness with different parameters. The current work outlines the entire experimental work done to expand the available knowledge on film cooling and its techniques. The paper discusses in detail the work done on gaseous and liquid film cooling and the research performed to date on flat plate cooling as well. The paper also outlines in brief the studies done on the mechanism of entrainment and film cooling. Studies performed to analyze the influence of various parameters such as blowing ratio, measurement flux ratio, density ratio, flow structure, hole geometry, surface roughness and boundary layer displacement thickness are also outlined in this paper. This paper thus outlines the entire experimental work performed on film cooling applied to flat plates to date.