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Laser-assisted machining is a widely used technique for preheating workpiece to reduce cutting forces and promote machinability in metal machining, thereby enhancing manufacturing quality and productivity. In setting laser-assisted machining parameters, the current practice typically relies on trial-and-error approaches. The uncertainties thereof could lead to adverse outcomes in product manufacturing, thus negating the potential benefits of this machining method. A clear understanding of workpiece thermal behaviour under laser spot heating is pivotal to developing a systematic basis for determining required preheating levels and optimised cutting variables for laser-assisted machining. In achieving this, the experimental methods are recognised to be largely impractical, if not tedious, due to instrument limitations and practicality of suitable non-intrusive measuring methods. Conversely, numerical methodologies do provide precise, flexible and cost-effective analytical options, warranting potential for insightful understanding on the transient thermal impact from laser preheating on rotating workpiece. Presenting such an investigation, this article presents a finite volume-based numerical simulation that examines and analyses the thermal response imparted by laser spot preheating on a rotating cylinder surface. On a rotating frame of reference using the ANSYS Fluent solver, the numerical model is formulated, accounting for transient heat conduction into the cylinder body and the combined convection and radiation loses from the cylinder surface. The model is comprehensively validated to ascertaining its high predictive accuracy and the applicability under reported laser-assisted machining operating conditions. The extensive parametric analyses carried out deliver clear insight into the dynamics of thermal penetration occurring within the workpiece due to laser spot preheating. This facilitates appropriate consideration of laser preheating intensity in relation to other operating variables to achieve necessary material softening depth at the workpiece surface prior to setting out on the subsequent machining process. Building upon the data generated, a practically simpler and cost-effective preheating parametric predictor is synthesised for laser-assisted machining using neural network principles incorporating the Levenberg–Marquardt algorithm. This predictive tool is trained and verified as a practical preheating guide for laser-assisted machining for a range of operating conditions.

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This paper describes a system and technique for controlling the attitude and direction of a quadrotor vertical take-off and landing unmanned aerial vehicle (VTOL UAV) using a horizontal thrust system (horizontal thruster), and hereby we call the system "Thruster Quad-rotor". The thruster quad-rotor operates by adjusting the rotational speed of each rotor's propellers to hold the quad-rotor's attitude (angular orientation and linear position in flight), while simultaneously control all direction horizontal motions in the horizontal plane using four thrusters installed on each arm of the quad-rotor. Each rotor is attached to an arm "tube". At the arm, on the tip, there is a thruster (electric duct fan -EDF). The four arms of the quad rotor are connected to the central body and aligned symmetrically at 45-degree angles to the X and Y axes forming a quad-rotor with "X" configuration. The horizontal thrusters enhance the effectiveness of the quad-rotor with novel design modifications; specifically, the horizontal thrusters increase the typical under-actuation to conventional quad-rotors. The application of the novel thruster concept leads to an increase in maneuvering of the UAV and an ability to resist winds and fly in tight spaces and scenarios, which presents flight's mission limitations. This paper will include the practicality of this new system, its conceptual and design aspects, and the mathematical modeling of the channels for the new UAV's enhanced control and guidance system.