Aerodynamic drag is one of the most opposing factors for ground vehicle. This becomes even more difficult while travelling through a tunnel. The Evacuated- Tube Trains (ETTs) or Hyperloop’s are a new concept of ground transportation presently being developed by many different companies. The main purpose of an Hyperloop can be displayed as a cheaper medium of ground transport, which could allow its consumers to propagate to different places at a cheaper and faster rate compared to the present day locomotives and road transport. Passengers can travel at over 700 mph in floating capsules that swoop along within gigantic low-pressure tubes that are either below or above surface. This study analyses the Hyperloop designs using Computational Fluid Dynamics software ANSYS FLUENT. The effects of operating speed, Capsule shape and internal tube pressure have been studied in this paper. The flow inside the tube is considered as turbulent and incompressible. The software simulation results show the significant effects of inside pressure and operating speed on the aerodynamic drag of the capsule. Study with different shapes for the Capsule’s front and rear end suggest the most optimum shape for least aerodynamic drag.

The main objective of this paper is to analyze various hydraulic oils and the effect of additives like nanomaterials in order to increase lubricity, counter friction, reduce wear, etc. A detailed list of additives is focused in this review which will enhance the performance and working of the hydraulic fluid by enhancing lubrication, modifying viscosity and cleaning engine deposits. Mineral oils or Synthetic hydrocarbon blends are used to derive lubricants. Although they lack properties of their own to fulfill the requirements set by the Original Equipment Manufacturers (OEMs). By using nanomaterials in mineral oils various advantages can be obtained. Various nanomaterials such as metal chalcogenides, soft metals, carbon-based materials, etc. are available which via mechanisms such as the rolling effect, protective film effect, etc., can change the various properties of hydraulic oils as required. Similarly, additives are added to hydraulic oils like viscosity index improvers, anti-wear agents which will improve the properties of the hydraulic oil by eliminating negative properties and improving the life of the fluid. These additives play a crucial role in sustainability of hydraulic oils and their size can be optimized to get better tribological characteristics. The increasing usage of these high performance additives in the country is projected to register a compound annual growth rate (CARG) of more than 1.5% during the forecast period (2021-2026). The review focusses on the improved performance of these nanomaterials and additives when added to the Hydraulic Fluid and will serve as a reference for future developments in the application of additives and nanotechnology in hydraulic oils.