The Defence Research Establishment Valcartier (DREV) in Canada and the TNO Prins Maurits Laboratory, Netherlands, have undertaken a collaborative activity (Integral Rocket Ramjet Demonstration Program - IRRDP) to demonstrate several of the key technologies of an air-breathing propulsion unit for a medium-range air-launched missile. An essential component of the propulsion system is the ducted rocket combustor, and as part of its development, experiments were conducted at TNO's direct-connect combustion test facility using existing sub-scale combustor hardware. To make the best use of the limited number of tests that could be carried out, a test matrix had to be carefully developed to determine which geometries and test conditions should be considered. This document presents much of the information used to develop this test matrix, to understand the phenomena investigated by other researchers, and identify which parameters were the most important for good air/fuel and combustor performance. Research work described includes visualization of flowfield within a model combustor in a water tunnel to better understand the air/fuel mixing, including flow stability; computational fluid dynamic modelling of the flow fields inside the combustor to determine whether the modelling was representative of the water tunnel tests; and modelling of additional combustor geometries.

The intention of this report is to demonstrate the utility of theflow visualization water tunnel in the field of experimentalfluid dynamics and also provide guidance to its prospectiveusers. A brief description of the facility and its ancillaryequipment is followed by a short description of the flowvisualization techniques. To emphasize the diversity of subjectstested in the water tunnel, a list of typical experiments and anumber of photographs are presented.

This study is a qualitative documentation of the main flow features that affect the aerodynamic performance under steady and unsteady maneuver conditions. The relevant fluid flow physics is not available presently and, hence, this thesis concentrated on generating those critical details. Towards this goal, model studies were conducted on the United States Air Force (USAF) geometry, described as same UCAV 1303, which is essentially a flying wing in the Naval Postgraduate School (NPS) water tunnel using dye-flow visualization technique. This study adapted the UCAV model 1303 for the NPS water tunnel by incorporating multiple ports for dye injection and was manufactured using rapid prototyping techniques. To obtain conditionally sampled flow images, especially for unsteady flow conditions, special phase locking circuitry was designed, fabricated and integrated with high resolution digital cameras and tunnel flow monitoring software. Flow visualization images at various Reynolds numbers, model attitudes and pitch rates were obtained. Strong vortical flow was observed as expected for a 47 degree delta-wing. The shallow sweep angle and tail-less geometry seemed to present some unusual aerodynamic characteristics in regard to vortex bursting.