This paper focuses on the demonstration of a new integrated aero-structural design method for aerospace vehicles. The approach combines an aero-structural analysis solver, a coupled aero-structural adjoint solver, a geometry-based analysis and design integration strategy, and an efficient gradient-based optimization algorithm. The aero-structural solver ensures highly accurate solutions by usin...

Several pin configurations were tested in an attempt to improve the aero-optical environment at large look-back angles over a cylindrical turret with a flat window. When small-diameter, tall pins were placed upstream of the cylindrical turret they created a partial blockage and formed a second shear layer. The second shear layer reduced the turbulent intensity of the main shear layer, with a re...

For an airborne optical system carried by a helicopter, aero-optic aberrations originate primarily from blade tip vortices that pass through the system field of view; these aberrations result from the reduced pressure and density in the vortex cores and the associated variations in the index-of-refraction. Using the weakly compressible model (WCM) previously developed at Notre Dame, aero-optic ...

Results of recent experimental measurements of the effect of passive boundary layer flow control method using Large-Eddy Break-Up devices on aero-optical distortions caused by turbulent subsonic boundary layers at a range of trans-sonic speeds are presented. Measurements were performed using a Malley probe to collect instantaneous onedimensional wavefronts with high resolution. Detailed statist...

A summary of research efforts for last several years on fluid-dynamics and aero-optics of hemisphereon-cylinder turrets with flat and conformal windows is presented. The topology of flow behind turrets and both steady and unsteady sources of optical distortions are discussed. Scaling laws for levels of optical aberrations are proposed and results of several experimental studies are compared and...

As demands for higher performance migrated from aircraft engines to land based gas turbines the need for EB welding came along also. The transfer of EB welding processes from relatively thin section components in aircraft turbines to land based aero derivative turbines is straightforward since the basic design and function of both aero and aero derivative components are the same or similar. How...

This report presents results of systematic experimental studies of various passive mitigation techniques to reduce aero-optical effects caused be turbulent boundary layers. Parametric studies of Large-Eddy BreakUp devices showed that aero-optical distortions can be suppressed by 45% for several boundary layer thicknesses. It was shown that moderate cooling of the wall also reduces aero-optical ...

A summary of research efforts for last several years on fluid-dynamics and aero-optics of hemisphere-on-cylinder turrets with flat or conformal windows is presented. A topology of flow behind turrets and both steady and unsteady sources of optical distortions are discussed. Scaling laws for levels of optical aberrations are proposed and results of several experimental studies are compared and d...

This article provides a critical review of aero-optics with an emphasis on recent developments in computational predictions and the physical mechanisms of flow-induced optical distortions. Following a brief introduction of the fundamental theory and key concepts, computational techniques for aberrating flow fields and optical propagation are discussed along with a brief survey Annu. Rev. Fluid ...

The demountable disk-drum aero-engine rotor is an important piece of equipment that greatly impacts the safe operation of aircraft. However, assembly looseness or crack fault has led to several unscheduled breakdowns and serious accidents. Thus, condition monitoring and fault diagnosis technique are required for identifying abnormal conditions. Customized ensemble multiwavelet method for aero-e...