Aeronautical Engineering

Fighter and Attack aircrafts represent some of the most exciting machines in the sphere of military power because of their design, speed, and weaponry. The sheer diversity of this category of aircraft, their evolution through military history, and the modern race to produce the most advanced and lethal fighter and attack aircraft yield a great deal of information and generates more interest than any other category of military aircraft. A design of a ground attack aircraft meeting the given requirements is presented in this paper. Design requirements were selected from market analysis. The most suitable requirements for aircraft design, extracted from market analysis were: range: 1,080 nm, maximum Mach number: 0.65, ceiling: 45,000 ft., payload: 16,000 lb., load factor: ranging from +4 to-3. The aircraft is capable of carrying one crew member. The aircraft is designed to follow a certain mission profile. This mission profile contains the flight segments like taxing, takeoff , climb, cruise, descend, attack and landing. The basic disciplines of aircraft design like aerodynamics, propulsion, engineering design, flight dynamics and management skill were carried out during the design process.

Unmanned Aerial Vehicles (UAVs) are considered as the largest integration of modern technology which have enormous potential for both military special operations & civil applications. UAVs are often preferred for missions that are too "dull, dirty, and dangerous". Its efficiency & success depends on factors such as performance, maintenance costs, design etc. This Paper aims to optimize the design of the wing of a medium size surveillance type UAV, by carrying out both analytical and computational analysis of aerodynamic and structural loads & also to study various materials and techniques for the fabrication of the designed wing. During the study, an attempt was made to familiarize with the theoretical aerodynamics, aircraft structural design methodologies and historical trends in wing design. The preliminary design dimensions as well as relevant loads of the wing structure were calculated based on the design lift and loading requirement for the UAV. The wing design was further analyzed by creating a software model of the UAV wing and simulating the flow and the structural loads using Solid Works and Design Foil software packages. The study attempts to record the steps followed, the calculations done, the theories applied and the references used during the project in a gradual progression to aid any future developmental work or study on wing design. The simplified analytical development of the conceptual design of a UAV wing can be used as a design reference for other types of aircrafts in some generic point of view.

We investigated the effect of arm pivot joints that are typically used during haptic exploration by evaluating four joints of the human arm (metacarpophalangeal joint of the index finger, wrist, elbow, and shoulder joints). Using a virtual stiffness discrimination task, a four-session psychophysical experiment was conducted with 38 participants (25 male and 13 female); each session was conducted with one of the four joints as the pivot joint during haptic exploration. The participants were asked to judge the stiffness of the top surface of two computer-generated cylinders by determining the stiffer one while using their dominant hand’s index finger. A two-alternative forced-choice procedure was employed by assigning one cylinder a constant stiffness value of 1.0 N/mm (standard side) and the remaining cylinder a variable stiffness value (comparison side). Using a custom-made stylus for the Geomagic TouchTM (3D Systems, Inc., Rock Hill, SC, USA) haptic interface, the participants were...

Loss of mass due to evaporation during molten metal levitation processing significantly influences the evaluation of density, viscosity and surface tension during thermophysical property measurement. Since there is no direct way to track the evaporation rate during the process, this paper describes a mathematical approach to track mass loss and quantify any changes in alloy composition as a function of time and temperature. The Ni-based super alloy CMSX-4 Plus (SLS) was investigated and a model was developed to predict the dynamic loss of mass with time and track the potential for composition shifts throughout each thermal cycle based on the Langmuir's equation for ideal solution behavior. Results were verified by post-test chemical analysis of key elemental constituents including Al, Cr, Ti, and Co where the error in composition for each element was less than 1 % when the activity of aluminum in solution was fixed at zero-effectively eliminating evaporation of aluminum for ground-based elec-trostatic levitation (ESL) testing in vacuum. This model predicts the mass evaporation for Al and Co within ± 6 % errors for CMSX-4 plus samples processed in ESL. Application of this technique to the space tests using the ESA ISS-EML facility shows that by conducting experiments in an inert shielding-gas environment, composition shifts due to differential relative evaporation become negligible and the composition is maintained within the desired limits. By tracking overall mass loss during testing the influence of evaporation on density measurements is discussed.

Electromagnetic levitation experiments in space are an essential tool for thermophysical property measurement and solidification studies. In light of the need for material properties as inputs to industrial process modeling, investigators need new tools for efficient experiment planning. MHD surrogate modeling is a parametric method for prediction of flow conditions during processing using the ISS-EML facility. Flow conditions in model Au, Zr, and Ti 39.5 Zr 39.5 Ni 21 samples are predicted using the surrogate model. For Au, flow is shown be turbulent in nearly all experimental conditions, making property measurement difficult. For Zr, the flow is turbulent with the heater on and laminar with the heater off, allowing for property measurement during free-cooling experiments only. For TiZrNi, the flow is laminar under all experimental conditions, indicating that TiZrNi is an excellent candidate for EML experiments. This surrogate modeling approach can be easily applied to other materials of interest, enabling investigators to choose materials that will perform well in levitation and to tailor experiment parameters to achieve desirable flow conditions. npj Microgravity (2020) 6:9 ; https://doi.

Increasing usage of Nickel-based super alloys in aerospace, power plant and nuclear reactors has made it necessary to model fluid flow during casting process. It is crucial to measure thermo-physical properties of these alloys accurately for this modelling purpose. Ni-based single crystal super alloy CMSX-4 plus were investigated for mass evaporation to analyze the mass loss using Electro Static Levitation (ESL) method. Two models were developed to predict the mass loss & dynamic mass during each thermal cycle. The first model predicts the rate of mass evaporation in ideal case where the evaporation is maximum with a correction factor. The second model predicts the mass evaporation with a correction of Aluminum activity which was calculated by evaluating the results from elemental analysis for Al, Cr, Ti, and Co. Both the models were applied and compared with the data obtained from another super alloy CMSX-10K using ESL. The models were also applied to CMSX-10K processed in Electro Magnetic Levitation (EML) to compare its accuracy for different sample size. Both models are not viable for analyzing space data yielding significant error. The 2nd model predicts the mass evaporation for Al & Co within ±6 % errors for CMSX-4 plus samples processed in ESL.

Conducting experiments in an inert shielding-gas environment limits the
likelihood for experiencing significant mass loss or compositional shifts due to
differential relative evaporation. Species-specific evaporation is proven to be below prescribed limits and near-real time monitoring of the potential for exposure is shown to be an effective tool to ensure astronaut safety. The activity coefficients for key constituents in the alloy are defined as a function of temperature for inclusion in next-generation toxicity tracking software.