Instead of commenting on Tejus's compound delta wing, I think we need to more detail on Tejus tailless configuration............
Feature of talless
Tailess fighters are relatively low cost.
But tailless aircraft face unique technical challenges in the area of flight controls:
(1) Control effectors exhibit non-linearities
(2) Typically significant aerodynamic interactions occur between the various controls effectors
(3) Effectors generate control moments about multiple axes, resulting in a highly coupled system
(4) Factors 1 through 3 make control allocation a very important issue
(5) Instabilities in multiple axes make control priorities
(6) Maximum vehicle efficiency is achieved by effectively using control redundancy, when it is available, to maximize lift and drag or minimize signature.
Benefits
--tailless aircraft directional control has been provided by spoilers or drag rudders.
spoilers and drag rudders have high attendant actuator requirements (a result of large hinge moments) and provide inadequate control power at high AOA.
--Reduced drag (compared to a tailed airplane)
--Reduced weight (compared to a 1995 SOA tailless airplane)
--Improved high-AOA agility and flying qualities
--Reduced actuator redundancy requirements
--Reduced number of Operational Flight Program (OFP) design cycles
--Reduced control-related accidents and mission-critical vulnerability.
Drag reduction
Minimum drag data for two configurations employing vertical tails shows that the vertical tail accounts for 5% to 10% of the total airplane minimum drag at a cruise Mach number of 0.9. Configuration features like area distribution and interference effects results in variation of the tail contribution. Nevertheless, 5% CDmin is still significant.
Risks
--risks and penalties of tailless aircraft when compared to conventional tailed aircraft.
Increased structural weight - A vertical tail and rudder are still the most weight efficient directional control and stabilization device for most of the flight envelope (see previous slide).
--Increased hydraulic power requirements - Primarily this increase is caused by increased actuator rate requirements of the innovative effectors.
--Increased FCS complexity. A tailless design incorporating innovative controls drives the configuration to include the integrated/adaptive flight control algorithms to mitigate the complexity involved with using traditional control design philosophies.
--Integration of innovative controls may compromise wing camber design on some configurations. This depends on planform and mission, and applies to wings having no leading-edge flaps. Note that the spoiler-slot-deflector controls do not carry this penalty.
