Jon Fleming

Techsburg, Inc. · Engineering

To document noise characteristics and provide validation data for acoustic modeling of rotor systems appropriate for eVTOL/UAM aircraft, the team of Techsburg, AVEC, and Virginia Tech performed an outdoor static test of a subscale 5-blade rotor. The testing was carried out as part of a program to demonstrate feasibility and performance of a quiet r...

Wake-ingesting propellers are attractive for low-speed propulsion due to their potential fuel savings and aircraft configuration benefits. Aeroacoustic concerns must be addressed for such installed pusher-propeller configurations, though limited validation of reduced-order models has constrained designers who require rapid and accurate predictions...

The emerging requirements for reduced emissions and quiet performance of air vehicles as outlined by NASA's Advanced Air Transport Technology Project has driven work in alternate propulsor-aircraft configurations. The ducted pusher-fan is a prime target for such innovation both because of the increased propulsive efficiency of boundary layer ingest...

The emerging requirements for reduced emissions and quiet performance of air vehicles as outlined by NASA's Advanced Air Transport Technology Project has driven work in alternate propulsor-aircraft configurations. The ducted pusher-propeller is a prime target for such innovation both because of the increased propulsive efficiency of boundary layer...

A comprehensive experimental investigation was initiated to evaluate the aerodynamic performance of a gas turbine exhaust diffuser/collector for various strut geometries over a range of inlet angle. The test was conducted on a 1/12th scale rig developed for rapid and accurate evaluation of multiple test configurations. The facility was designed to...

A comprehensive experimental investigation was initiated to evaluate the aerodynamic performance of a gas turbine exhaust diffuser/collector for various strut geometries over a range of inlet angle. The test was conducted on a 1/12th scale rig developed for rapid and accurate evaluation of multiple test configurations. The facility was designed to...

A comprehensive experimental investigation was initiated to evaluate the aerodynamic performance of a gas turbine exhaust diffuser/collector for various strut geometries over a range of inlet angle. The test was conducted on a 1/12th scale rig developed for rapid and accurate evaluation of multiple test configurations. The facility was designed to...

The effectiveness of active flow control for the reduction of flow distortion in boundary layer-ingesting serpentine inlets was examined. The intended purpose of the flow control was to redistribute the ingested low-momentum boundary-layer fluid around the periphery of the diffuser to reduce the flow distortion at the engine face. A variety of diff...

The development of high-temperature, high-efficiency microthermoelectric generator modules is discussed. They are integrated onto unmanned microair-vehicle (MAV) propulsion systems. A 1×1×0.2 cm module that produces up to 800mW at a module thermoelectric efficiency of 6 to 7% is demonstrated. The module is integrated with small internal combustion...

An experimental program is conducted to demonstrate the potential of a novel sensing technique for flow control system to alleviate problems caused by propulsion inlet/boundary layer interactions which are commonly seen in advanced propulsion-airframe integration (PAI) concepts. The work carried out in this project included aerodynamic and micropho...

There is an increasing need for and development effort in small UAVs (<100 lbs) that can be deployed at the platoon or small unit level in the military. These new vehicles need to be implemented as lightweight, man-deployable systems, yet still retain the essential mission capabilities that larger, more complex UAV systems offer. Since UAV power re...

There is an increasing need for and development effort in small UAVs (<100 lbs) that can be deployed at the platoon or small unit level in the military. These new vehicles need to be implemented as lightweight, man-deployable systems, yet still retain the essential mission capabilities that larger, more complex UAV systems offer. Since UAV power re...

A variety of experiments have revealed some generalizations about the behavior of three-dimensional turbulent boundary layers. These include the anisotropic nature of the eddy viscosity and the lags between the mean flow gradients and the turbulence. The v rms normal-to-wall velocity fluctuation appears to be an important velocity scale. The parame...

Laser Doppler velocimetry (LDV) measurements and hydrogen bubble flow visualization techniques were used to examine the near-wall flow structure of 2D and 3D turbulent boundary layers (TBLs) over a range of low Reynolds numbers. The goals of this research were (1) an increased understanding of the flow physics in the near wall region of turbulent b...

Extensive measurements were conducted in an incompressible turbulent flow around the wing-body junction formed by a 32 semi-elliptic nose/NACA 0020 tail section and a flat plate. Mean and fluctuating velocity measurements were performed adjacent to the wing and up to 11.56 chord lengths downstream. The appendage far wake region was subjected to an...

A variety of methods have been developed to obtain acurate frequency estimates from laser Doppler velocimetry (LDV) signals. Rapid scanning and fiber optic LDV systems require robust methods for extracting accurate frequency estimates with computational efficiency from data with poor signal-to-noise ratios. These methods typically fall into two gen...