A lateral jet in a supersonic crossflow creates a highly complex three-dimensional flow field which is not easily predicted. The aim of this research was to assess the use of a RANS based CFD method to simulate a lateral jet in supersonic crossflow interaction by comparing the performance of available RANS turbulence models. Four turbulence models were trialled in increasingly complex configurations; a flat plate, a body of revolution and a body of revolution at incidence. The results of this numerical campaign were compared to existing experimental and numerical data. Overall the Spalart-Allmaras turbulence model provided the best fit to experimental data. The performance of the lateral jet as a reaction control system was assed by calculating the force and moment amplification factors. The predicted flowfield surrounding the interaction was analysed in detail and was shown to predict the accepted shock and vortical structures. The lateral jet interaction flowfield over a body of revolution was shown to be qualitatively the same as that over a flat plate. An experimental facility was designed and manufactured allowing the study of the lateral jet interaction in Cranfield University’s 2 ½” x 2 ½” supersonic windtunnel. The interaction was studied with a freestream Mach number of 1.8, 2.4 & 3.1 and over a range of pressure ratios (50≤PR≤200). Levels of unsteadiness in the interaction were measured using high bandwidth pressure transducers. The level of unsteadiness was quantified by calculating the OASPL of the pressure signal. OASPL was found to increase with increasing levels of PR or MPR and to decrease with increases of Mach number. The levels of unsteadiness found were low with the highest levels found downstream of the jet.

This paper will investigate the development of a landing footprint for a re-entry vehicle. Vehicles can re-enter the atmosphere with a range of orientations, velocities and flight path angles. The central question is whether a vehicle with any combination of these states can be brought to an acceptable landing condition at a particular landing site and with a particular landing speed. To aide in this investigation several models must be implemented, including that of the atmosphere, the vehicles, the Earth, and the aerodynamics. A detailed analysis of the aerodynamic model will be treated, and the equations of motion subject to these aerodynamic laws will then be compared to results from existing atmospheric reentry software. The principles of optimization will then be employed to generate the footprint of landable states, based on maximum and minimum possible downrange distances, for two vehicle concepts.

This study has investigated the conceptual feasibility of a rocket propelled kinetic energy penetrator (KEP), designed for the handheld recoilless rifle Carl-Gustaf® 84 mm calibre system, from an exterior ballistics perspective. The methodology is based upon evaluating the aerodynamic properties of different conceptual design proposals through CFD-simulations and then performing trajectory analysis to assess their exterior ballistic performance. In particular, the main focus has been to optimize the stability, velocity and spin rate of the KEP. The results of the study indicates that the final chosen KEP design retains, from an aerodynamic perspective, longitudinal stability for Mach numbers up to 4.5, regardless if the rocket motor is ignited or not. Furthermore, if using NK1384 propellant, the final chosen design in the study is, according to the calculations, able to achieve a maximum velocity of 0.7⋅v_ref and retain a minimum velocity of 0.628⋅v_ref in the horizontal range of [0.318⋅x_ref,0.648⋅x_ref] measured from the shooter. In addition, the angular spin velocity achieves a maximum value of 15.5 Hz, satisfying the performance limitation of the rocket motor which only functions properly for frequencies up to 30 Hz, while simultaneously providing a sufficiently considered spin rate in order to average possible thrust and mass deviations of the KEP. The results also show that if using ammonium dinitramide (ADN) propellant, the KEP is able to achieve a maximum velocity of 0.786⋅v_ref, retain a minimum velocity of 0.628⋅v_ref in the horizontal range of [0.28⋅x_ref,0.98⋅x_ref] and achieve a maximum spin rate of 17.5 Hz. / Den här studien har på ett konceptuellt plan undersökt om det är möjligt att konstruera en raketdriven kinetisk energi-pil (KE-pil), designad för det rekylfria Carl-Gustaf® 84 mm granatgeväret. Studiens metod grundade sig i att undersöka olika konceptuella designförslag och utvärdera deras aerodynamiska egenskaper genom CFD-simulationer för att sedan genomföra bansimuleringar och bedöma deras ytterballistiska prestanda. Framför allt fokuserades det på att optimera KE-pilens stabilitet, hastighet och rollvinkelfrekvens. Resultaten från studien indikerar att det ur ett aerodynamiskt perspektiv är möjligt att statiskt stabilisera KE-pilen för Machtal upp till 4.5, oavsett om raketmotorn är antänd eller ej. Vidare, vid implementering av NK1384-krut lyder prestandaspecifikationerna enligt följande för studiens slutgiltiga designförslag enligt genomförda beräkningar. Den maximalt uppnådda hastigheten är 0.7⋅v_ref och en minimumhastighet om 0.628⋅v_ref kan upprätthållas inom det horisontella intervallet [0.318⋅x_ref,0.648⋅x_ref ] räknat ifrån skytten. Vidare uppnås en maximal rollvinkelfrekvens på 15.5 Hz, vilket tillfredsställer raketmotorns prestandabegränsning om en maximal rollvinkelfrekvens på 30 Hz, samtidigt som detta är en god frekvens för att utjämna eventuella avvikelser från raketmotors avsedda massflödesriktning tillika avsedd massdistribution hos KE-pilen. Om krutet i stället byts ut till ammoniumdinitramid (ADN) kan en maximal hastighet om 0.786⋅v_ref uppnås, en minimumhastighet om 0.628⋅v_ref kan upprätthållas inom intervallet [0.28⋅x_ref,0.98⋅x_ref ] och den maximala rollfrekvensen är 17.5 Hz.