Abstract—Producer gas is a biomass derived gaseous fuel which is extensively used in internal combustion engines for power generation application. Unlike the conventional hydrocarbon fuels (Gasoline and Natural gas), the combustion properties of producer gas fuel are much different. Therefore, setting of optimal spark time for efficient engine operation is required. Owing to the fluctuating ten...

This lecture deals with the application of numerical optimization for aerodynamic design of high-lift systems, which is a multi-objective constraint design problem. The applied mathematical fundamentals of numerical optimization are briefly outlined. A description of the design targets and constraints for high-lift wings is given, followed by a detailed analysis of the properties of the flow ca...

Numerical methods are not always convergent especially in higher velocities when shock waves are involved. A comparison analysis is performed to study the supersonic flow over conical bodies of three different cross sections circular, elliptic and squircle (square with rounded corners) shaped using  Perturbation techniques to find flow variables analytically. In order to find lift and drag forc...

We study here the motion of a spherical gas bubble in a solid body rotating flow of clean silicon oil, to avoid contamination of interface. From the measurement of its equilibrium position, lift and drag forces are determined. Five different silicon oils have been used, providing five different viscosities and Morton numbers. For spherical bubbles the drag coefficient is at first order the same...

An aerodynamic design optimization problem of a three-dimensional flapping wing is explored with the multiobjective design exploration framework coupled with a Navier-Stokes solver. The results show that there is a tradeoff among lift maximization, thrust maximization, and required power minimization. The results also show that strong vortex is generated in both down stroke and up stroke motion...

Introduction: Expiratory upper airway obstruction during bag-mask ventilation is not well characterized. Methods: An audit was done to assess expiratory obstruction in 90 adult surgical patients undergoing bag-mask ventilation during the induction of general anaesthesia. Results: Clinicians experienced difficulty delivering gas to the lungs when the head was neutral in 52 of 90 patients (58%; i...

Laser-induced forward transfer (LIFT) is a high-resolution direct-write technique, which can print a wide range of liquid materials without a nozzle. In this process, a pulsed laser initiates the expulsion of a highvelocity micro-jet of fluid from a thin donor film. LIFT involves a novel regime for impulsively driven free-surface jetting in that viscous forces developed in the thin film become ...