SASTRA University Mistral (concept design)

Mistral (concept design)
School of Mechanical Engineering
Shanmugha Arts, Science, Technology & Research Academy (SASTRA) Deemed University
Thanjavur, Tamil Nadu, India
www.sastra.edu

The Shanmugha Arts, Science, Technology & Research Academy, also known as SASTRA, is a private and deemed university in the town of Thirumalaisamudram, Thanjavur district, Tamil Nadu, India. SASTRA was founded in 1984.

The design team for this electric vertical takeoff and landing (eVTOL) concept design is from the School of Mechanical Engineering at the Shanmugha Arts, Science, Technology & Research Academy (SASTRA) Deemed University. The design team is comprised of Arumugam Akash, Vijayaraj Stephen Joseph Raj, Ramesh Sushmitha, Boga Prateek, Sankarasubramanian Aditya and Veloorillom Madhavan Sreehari. The team of designers call themselves "The Huggy’s Birds". The academic editors are Rafael Casado and Aurelio Bermúdez.

The name of the abstract is "Design and Analysis of VTOL Operated Intercity Electrical Vehicle for Urban Air Mobility". The reason for the abstract is due to contemporary delays being caused by traffic congestion and to make an all-electric air taxi that can solve this problem which is also environmentally friendly (no carbon monoxide emissions). The aircraft has been designed to fly passengers for on-demand air taxi service within the same city.

The team studied many aspects of the aircraft including the flight controls, avionics, the propeller design (including tilt-props) and the electric motors. The design team also studied the mission profile the aircraft, initial sizing and payload-range. The team also estimated weight of the wings, estimated weight of the fuselage, estimated weight of the V-tail and estimated the weight of the landing gear. In addition, the design team studied the cargo configuration for the aircraft.

The abstract covers these topics:

• Introduction
• Literature Study
• Initial design and discussion
• Layout (of the aircraft)
• Mission Profile and Preliminary Sizing Calculations
• Airfoil and Wing Planform Selection
• Geometric Sizing
• Design Parameters
• Component Placement and Center of Gravity Estimation
• Aerodynamic Analysis
• Structural Analysis and material selection
• Aircraft Performance
• Aircraft Stability and Control
• Cost Estimation and Technological Forecast
• Relevance of Present Design and Analysis
• Conclusions

The Mistrel is a concept design eVTOL air taxi that holds one pilot and four passengers. The aircraft looks similar to a small general aviation aircraft. The estimated cruise speed is 200-250 km/h (124-155 mph), has a range of 500 km (311 miles) and has a cruise altitude of 2,000 m (6,562 ft). The estimated empty weight of the aircraft is 1,755 kg (3,869 lb), has a maximum payload of 500 kg (1,102 lb) and has a maximum takeoff weight of 1,255 kg (2,767 lb).

The aircraft has six tilt-propellers and has six electric motors which are powered by batteries. The design team chose tilt-props instead of tilt-wings due to the complexity of tilt-wings and the stress that tilt-wings can have on an aircraft's fuselage. The aircraft has a fairly typical fuselage (which was engineered specifically for eVTOL air taxi service), one high main wing, a V-tail and retractable tricycle wheeled landing gear.

The fuselage is the foremost important section of the aircraft, according to the design team. The shape of the fuselage was selected with the aim of increasing the pilot’s visibility of the immediate surroundings during forward flight and at landing zones on the ground or on rooftop vertiports. An up-sweep of 15 degrees was designed in the rear of the fuselage for ease of cargo loading and smooth flow to decrease drag. There is a luggage compartment behind the passenger seats.

The material components for the interior were meticulously selected by considering thermal and acoustic insulation of the cabin. Other parameters such as durability, fire and static resistance and ease of cleaning were also considered. The team was also very careful to keep the weight of the aircraft as low as possible.

The Mistral eVTOL aircraft has been designed to be used for both air taxi service and air cargo service. The sales price per aircraft is expected to be between $14.83-$17.36 million USD.

Specifications:

• Aircraft type: eVTOL passenger and air cargo aircraft
• Piloting: 1 pilot
• Capacity: 4 passengers
• Cruise speed: 200-250 km/h (124-155 mph)
• Range: 500 km (311 miles)
• Flight time: Unknown
• Cruise altitude: 2,000 m (6,562 ft)
• Empty weight: 1,755 kg (3,869 lb)
• Maximum payload: 500 kg (1,102 lb)
• Maximum takeoff weight: 1,255 kg (2,767 lb)
• Propellers: 6 tilt-propellers
• Electric motors: 6 electric motors
• Power source: Battery packs (placed inside the wing with vents allowing the batteries to be cooled during flight)
• Fuselage: Aluminum
• Windows: Panoramic wrap around windows allowing forward, left, right visibility, for spectacular views with a solid roof above the passenger compartment
• Wings: 1 main high wing
• Tail: V-tail
• Landing gear: Retractable tricycle wheeled landing gear
• Safety features: Distributed Electric Propulsion (DEP), provides safety through redundancy for its passengers and/or cargo. DEP means having multiple propellers (or ducted fans) and motors on the aircraft so if one or more propellers (ducted fans) or motors fail, the other working propellers (or ducted fans) and motors can safely land the aircraft. There are also redundancies in the sub-systems of the aircraft. In case of emergency and the aircraft looses all power, the aircraft can glide and land on a runway or roadway.

Company Insights:

• Wikipedia

Resources:

• SASTRA Deemed University website
• SASTRA Deemed University Facebook
• SASTRA Deemed University Twitter
• SASTRA Deemed University YouTube Channel
• Article:  Design and Analysis of VTOL Operated Intercity Electrical Vehicle for Urban Air Mobility, MDPI, Dec. 22, 2021