PUBLICATIONS
| Broughton, K. M., Williams, D. R., Brooks, M. J., Pitot de la Beaujardiere, J., “Development of the Phoenix-1B Mk II 35 km Apogee Hybrid Rocket”, 2018 Joint Propulsion Conference, AIAA Propulsion and Energy Forum, Cincinnati, OH, 2018. |
| Velthuysen, T., Broughton, K. M., Brooks, M. J., Pitot de la Beaujardiere, J., Lineberry, D. M., Tingley, E., “Safety Aspects of Nitrous Oxide Use in Hybrid Rocket Motor Design and Testing”, 2018 Joint Propulsion Conference, AIAA Propulsion and Energy Forum, Cincinnati, OH, 2018. |
| Wunderlin, N., Martin, D., Pitot, J., Brooks, M., “Design Options for a South African Small-Satellite Launch Vehicle”, 2018 Joint Propulsion Conference, AIAA Propulsion and Energy Forum, Cincinnati, OH, 2018. |
| Veale, K., Adali, A., Pitot, J., Bemont, C., “The structural properties of paraffin wax based hybrid rocket fuels with aluminium particles”, Acta Astronautica, Vol. 151, 864-873, 2018. |
| Veale, K., Adali, A., Pitot, J., Brooks, M., “A review of the performance and structural considerations of paraffin wax hybrid rocket fuels with additives”, Acta Astronautica, Vol. 141, 196-208, 2017. |
| Du Clou S., Brooks M.J., Lear W.E., Sherif S.A. and Khalil E.E. “Performance and Control of a Pulse Thermal Loop Heat Transport System”, AIAA Journal of Thermophysics and Heat Transfer, Vol. 29, No. 4, 826-834, 2015 |
| Genevieve B., Pitot J., Brooks M.J., Chowdhury S., Veale K., Leverone F., Balmogim U. and Mawbey R., “Flight Test of the Phoenix-1A Hybrid Rocket”, 51st AIAA/SAE/ASEE Joint Propulsion Conference, Orlando, Florida, 2015 |
| Balmogim, U., Brooks M., Pitot de la Beaujardiere J-F, Veale K., Genevieve B. and Roberts L.W., “Preliminary Design of the Phoenix-1B Hybrid Rocket”, 51st AIAA/SAE/ASEE Joint Propulsion Conference, Orlando, Florida, 2015 |
| Fitzgerald D.J., Smith G.D.J., Brooks M.J. and Snedden G.C., “Preliminary Design of a Gas Turbine to Drive a South African Commercial Booster Engine”, 51st AIAA/SAE/ASEE Joint Propulsion Conference, Orlando, Florida, 2015 |
| Veale K., Brooks M.J., Pitot de la Beaujardiere J-F., “Structural Performance of Large Scale Paraffin Wax Based Fuel Grains”, 51st AIAA/SAE/ASEE Joint Propulsion Conference, Orlando, Florida, 2015 |
| Page M., Brooks M.J., Roberts L.W. and Bemont C., “Modelling and Experimental Validation of a Loop Heat Pipe”, R&D Journal of the South African Institution of Mechanical Engineering 29, 26-35, 2013 |
| Genevieve B., Chowdhury S.M., Brooks M.J., Pitot de la Beaujardiere J., Veale K. and Roberts L., “The Phoenix Hybrid Sounding Rocket Program: A Progress Report 2012”, 48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Atlanta, Georgia, 2012 |
| Smyth J., Bindon J., Brooks M., Smith G. and Snedden G., “The Design of a Kerosene Turbopump for a South African Commercial Launch Vehicle”, 48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Atlanta, Georgia, 2012 |
| Page M., Brooks M.J., Bemont C. and Roberts L.W., “Performance validation of a steady-state loop heat pipe model”, AIAA International Energy Conversion Engineering Conference, Atlanta, Georgia, 2012 |
| Du Clou S., Brooks, M.J., Lear W.E., Sherif, S.A. and Khalil E.E., “An Ejector Transient Performance Model for Application in a Pulse Refrigeration System”, AIAA 2011-5804, 9th AIAA International Energy Conversion Engineering Conference, San Diego, California, 2011 |
| Leverone F.K., Pitot de la Beaujardiere, J., Brooks M.J., Roberts L.W., Recent Advances in South Africa’s Phoenix Hybrid Sounding Rocket Programme, IAC-11-D2.7.3, 62nd International Astronautical Congress, Cape Town, 2011 |
| Genevieve B., Brooks M.J., Pitot de la Beaujardiere J. and Roberts L.W., “Performance Modeling of a Paraffin Wax/Nitrous Oxide Hybrid Rocket Motor”, 49th AIAA Aerospace Sciences Meeting, Orlando, 2011 |
| Chowdhury S., Pitot de la Beaujardiere J., Brooks M.J. and Roberts L.W., “An Integrated Six Degree-of-Freedom Trajectory Simulator for Hybrid Sounding Rockets”, 49th AIAA Aerospace Sciences Meeting, Orlando, 2011 |
Graduate dissertations
2018
Advisors: Dr. Mike Brooks
Co-advisors: Prof Graham Smith and Dr Glen Sneddon (CSIR)
The deployment of micro- and nanosatellites has greatly increased over the past few decades with advances in miniaturized electronics for communication, imaging and attitude control. The South African satellite industry is now also currently developing two microsatellites and nanosatellites for launch by foreign providers. The outsourcing of launch services to foreign providers is costly and can lead to unanticipated delays. In this context, the UKZN Aerospace Systems Research Group (ASReG), in conjunction with the Council for Scientific and Industrial Research (CSIR) has begun designing a modular and compact liquid propulsion engine (LOX/RP-1) named SAFFIRE (South AFrican First Integrated Rocket Engine). This dissertation details the design and analysis of the liquid oxygen pump that delivers the oxidiser to the SAFFIRE combustion chamber at high pressure, where the propellants are burnt and expelled, generating thrust. The pump is electrically powered as opposed to the conventional turbine-driven turbopump, to further simplify start-stop procedures and reduce the complexity of the engine. The pump’s operating conditions were determined by an engine performance analysis, with these results forming the initial conditions for the pump design process. The oxidiser pump is required to deliver a mass flow rate of 6.13 kg/s at a pressure of 62.8 bar. The pump was designed using conventional centrifugal pump design procedures, with special considerations taken due to the working temperature of liquid oxygen being -183°C. The final one-dimensional design for the impeller was developed using the commercial software PUMPAL™, which was provided by the CSIR. A 3D impeller geometry was developed by importing the one-dimensional design into AxCent™, where quasi-3D Multiple Stream Tube (MST) analysis and full 3D computational fluid dynamics (CFD) simulations were performed. The impeller design was refined multiple times until the parameters set by the engine performance analysis were met. The AxCent™ analyses determined that low-pressure zones occurred at the inlet of the pump impeller. Hence Star-CCM+™, which has a more robust computational solver and allows for a full transient, multiphase CFD to be performed, was employed to analyse any potential cavitation affects. The results from Star-CCM+™ and AxCent™ were compared and designs altered until a final design was realized that met the prescribed performance parameters. The final pump impeller has an outer diameter of 86 mm, delivering a mass flow rate of 6.13 kg/s at a pressure of 64.2 bar. The pump operates at an efficiency of 60.8% requiring a power input of 51.96 kW at a rotational speed of 26000 rpm.
2017
Advisor: Dr. Mike Brooks
Co-advisors: Dr Jean Pitot and Kirsty Veale
In August 2014, South Africa’s first university-based hybrid rocket, Phoenix-1A, was launched at the Overberg Test Range near Cape Agulhas. The vehicle suffered nozzle and parachute failures during flight which, together with a reduced oxidiser load, reduced the nominal design apogee of 10 km to 2.5 km. The aim of this research was to improve on the design and performance of the prototype demonstrator and thereby develop a workhorse hybrid sounding rocket, named Phoenix-1B, to serve as a reliable platform for future hybrid rocket research at the University of KwaZulu-Natal (UKZN). Analysis of Phoenix-1A shortcomings served as the starting point for the new design, which utilises a paraffin wax and nitrous oxide propellant combination. The focus of this research was the propulsion system, with specific attention being paid to the nozzle and injector designs. In addition, an aerodynamic study was applied to the 1 m long ¾ parabolic nose cone and four tapered swept fins. Final design of the aluminium oxidiser tank and combustion chamber bulkheads incorporated finite element analyses to ensure an operational safety factor greater than 1.5. The oxidiser tank and combustion chamber assemblies were pressure tested to 80 and 60 bars respectively. A key output of the present work is an analysis of the effect of aluminium loading in the paraffin wax fuel grain, which indicated a potential rocket mass reduction of 23 kg when transitioning from a pure paraffin grain to one containing 40% aluminium by mass. The analysis also indicated that combustion temperature rises with aluminium loading, increasing from 3300 K for pure paraffin to 3600 K for 40% aluminised fuel. Consequently, an iterative transient thermo-structural analysis was conducted on the nozzle, resulting in an optimised design able to sustain the higher operating temperatures as well as mitigate the risk of failure as seen with Phoenix-1A. The final manufactured composite nozzle has a throat diameter of 32 mm, an expansion ratio of 6.38, and a length of 156 mm. The nozzle has a steel casing which provides structural support to the silica phenolic insulation and graphite throat insert. A two phase CFD analysis, coupled with analytical mass flow rate models, was used to configure the axial injector and reduce the potential for combustion instabilities associated with the nitrous oxide flow. The Phoenix-1B motor has a design thrust of 5 kN to propel the fully loaded vehicle, with a mass of 70 kg, a length of 4.3 m and a diameter of 164 mm, to an altitude of 16 km.
2015
Advisor: Graham Smith
Co-advisors: Mike Brooks, Prof Jeff Bindon and Dr Glen Snedden (CSIR)
This dissertation presents the validation of a universal impeller test rig, designed and constructed at the University of KwaZulu-Natal (UKZN). The research was conducted as part of UKZN’s Aerospace Systems Research Group’s (ASReG) work into liquid rocket propulsion. The rig will be used to evaluate the performance of impellers for use in commercial launch vehicle fuel turbopumps. Head rise versus flow rate characteristics, as well as cavitation performance are to be assessed by the rig. The power requirements of the impellers necessitated the reduction in rotational speed and geometric size of the test case. Scaling laws and dimensionless numbers were used to predict performance of a test impeller. Validation of the rig and testing procedures was performed using a standard industrial KSB ETA 125 – 200 centrifugal pump, by comparing the experimental results with those of the supplier. Head rise characteristics were determined by measuring the change in pressure between the inlet and discharge of the pump and then plotted against the flow rate for varying system heads. Cavitation performance was assessed by decreasing the inlet pressure while maintaining a constant flow rate. This was performed at various flow rates within the range of operation. Head breakdown, vibration and noise levels, both in the time and frequency domains, were used to assess the cavitation performance. The head rise versus flow characteristics of the pump, determined on the rig, showed good agreement with the supplier’s data. Cavitation performance, determined by head breakdown, was also in accordance with the supplier. It was found that both the vibration and general noise levels increased, indicating the presence of cavitation, before any head breakdown was detected. By monitoring the level of the high frequency noise (> 10 kHz) the presence of cavitation was detected at a significantly higher inlet pressure than would be suggested by the head breakdown approach.
2014
Advisor: Mike Brooks
Co-advisors: Jean Pitot and Prof Lance Roberts
In this dissertation, UKZN’s in-house Hybrid Rocket Performance Simulator (HYROPS) software is used in the design of Phoenix-2A, a proposed hybrid rocket for delivering a 5 kg instrumentation payload to an apogee altitude of 100 km. As a benchmarking exercise, HYROPS was first validated by modelling the performance of existing sub-orbital sounding rockets similar in apogee to Phoenix-2A. The software was found to approximate the performance of the published flight data within 10%. A generic methodology was then proposed for applying HYROPS to the design of hybrid propellant sounding rockets. An initial vehicle configuration was developed and formed the base design on which parametric trade studies were conducted. The performance sensitivity for varying propulsion and aerodynamic parameters was investigated. The selection of parameters was based on improving performance, minimising cost, safety and ease of manufacturability. The purpose of these simulations was to form a foundation for the development of the Phoenix-2A vehicle as well as other large-scale hybrid rockets. Design chamber pressure, oxidiser-to-fuel ratio, nozzle design altitude, and fin geometry were some of the parameters investigated. The change in the rocket’s propellant mass fraction was the parameter which was found to have the largest effect on performance. The fin and oxidiser tank geometries were designed to avoid fin flutter and buckling respectively. The oxidiser mass flux was kept below 650 kg/m2s and the pressure drop across the injector relative to the chamber pressure was maintained above 15% to mitigate the presence of combustion instability. The trade studies resulted in an improved design of the Phoenix-2A rocket. The propellant mass of the final vehicle was 30 kg less than the initial conceptual design and the overall mass was reduced by 25 kg.
Advisor: Mike Brooks Co-advisors
Prof. Graham Smith, Prof. Jeff Bindon and Dr. Glen Snedden (CSIR)
South Africa is one of the few developing countries able to design and build satellites; however it is reliant on other nations to launch them. This research addresses one of the main technological barriers currently limiting an indigenous launch capacity, namely the development of a locally designed liquid fuel turbopump. The turbopump is designed to function in an engine system for a commercial launch vehicle (CLV) with the capacity to launch 50-500 kg payloads to 500 km sun synchronous orbits (SSO) from a South African launch site. This work focuses on the hydrodynamic design of the impeller, vaneless diffuser and volute for a kerosene (RP-1) fuel pump. The design is based on performance analyses conducted using 1D meanline and quasi-3D multi-stream tube (MST) calculations, executed using PUMPAL and AxCent software respectively. The pump is designed to run at 14500 rpm while generating 889 m of head at a flowrate of 103.3 kg/s and consuming 1127.8 kW of power. As testing will be a critical component in the University of KwaZulu-Natal’s turbopump research program, this work also addresses the scaling down of the impeller for testing. The revised performance and base dimensions of the scaled impeller are determined using the Buckingham-Pi based scaling rules. The test impeller is designed to run at 5000 rpm with a geometric reduction of 20%, using water as the testing medium. A method for maintaining a similar operating characteristic to the full scale design is proposed, whereby the scaled impeller’s blade angle distribution is modified to maintain a similar diffusion characteristic and blade loading profile.
2013
Advisor: Jean Pitot
Co-advisors: Mike Brooks and Prof Lance Roberts
This work describes the development of a hybrid rocket propulsion system for a reusable sounding rocket, as part of the first phase of the UKZN Phoenix Hybrid Sounding Rocket Programme. The dissertation details the development of the Hybrid Rocket Performance Code (HRPC) together with the design, manufacture and testing of Phoenix-1A’s propulsion system. The Phoenix-1A hybrid propulsion system utilises SASOL 0907 paraffin wax and nitrous oxide as the solid fuel and liquid oxidiser, respectively. The HRPC software tool is based upon a one-dimensional, unsteady flow mathematical model, and is capable of analysing the combustion of a number of propellant combinations to predict overall hybrid rocket motor performance. The code is based on a two-phase (liquid oxidiser and solid fuel) numerical solution and was programmed in MATLAB. HRPC links with the NASA-CEA equilibrium chemistry programme to determine the thermodynamic properties of the combustion products necessary for solving the governing ordinary differential equations, which are derived from first principle gas dynamics. The combustion modelling is coupled to a nitrous oxide tank pressurization and blowdown model obtained from literature to provide a realistic decay in motor performance with burn time. A targeted total impulse of 75 kNs for the Phoenix-1A motor was obtained through iterative implementation of the HRPC application. This yielded an optimised propulsion system configuration and motor thrust curve.
Advisor: Mike Brooks Co-advisors
Prof Lance Roberts and Clinton Bemont
The Loop Heat Pipe (LHP) is a passive, two-phase heat transfer device used, most commonly, for thermal management of aerospace and aeronautical electronic equipment. This research had two aims. Firstly, to create and validate a robust mathematical model of the steady-state operation of an LHP for terrestrial high heat flux electronics. Secondly, to construct an experimental LHP, including a sintered porous wick, which could be used to validate the model and demonstrate the aforementioned heat exchange and gravity resistant characteristics. The porous wick was sintered with properties of 60% porosity, 6.77×10-13 m2 permeability and an average pore radius of 1 μm. Ammonia was the chosen working fluid and the LHP functioned as expected during horizontal testing, albeit at higher temperatures than anticipated. The heat load range extended to 60 W, 50 W and 110 W for horizontal, gravity-adverse and gravity-assisted operation respectively. Because of certain simplifying assumptions in the model, the experimental results deviated somewhat from predicted values at low heat loads. Model accuracy improved as the heat load increased. The experimental LHP behaved as expected for 5° and 10° gravity-assisted and gravity-adverse conditions, as well as for transport line variation, in which performance was assessed while the total tubing length was increased from 2.5 m to 4 m.
Advisor: Mike Brooks Co-advisors Jean Pitot and Prof Lance Roberts This dissertation describes the development of the Hybrid Rocket Performance Simulator (HYROPS) software tool and its application towards the structural design of the reusable, 10 km apogee capable Phoenix-1A hybrid sounding rocket, as part of the UKZN Phoenix programme. HYROPS is an integrated 6–Degree of Freedom (6-DOF) flight performance predictor for atmospheric and near-Earth spaceflight, geared towards single-staged and multi-staged hybrid sounding rockets. HYROPS is based on a generic kinematics and Newtonian dynamics core. Integrated with these are numerical methods for solving differential equations, Monte Carlo uncertainty modeling, genetic-algorithm driven design optimization, analytical vehicle structural modeling, a spherical, rotating geodetic model and a standard atmospheric model, forming a software framework for sounding rocket optimization and flight performance prediction. This framework was implemented within a graphical user interface, aiming for rapid input of model parameters, intuitive results visualization and efficient data handling. The HYROPS software was validated using flight data from various existing sounding rocket configurations and found satisfactory over a range of input conditions. An iterative process was employed in the aerostructural design of the 1 kg payload capable Phoenix-1A vehicle and CFD and FEA numerical techniques were used to verify its aerodynamic and thermo-structural performance. |
Advisor: Mike Brooks
Co-advisor: Prof Lance Roberts
In this study a semi-passive pulse thermal loop (PTL) was designed and experimentally validated. It provides improved heat transfer over passive systems such as the loop heat pipe in the moderate to high heat flux range and can be a sustainable alternative to active systems as it does not require an electric pump. This work details the components of the engineering prototype and characterizes their performance through the application of compressible and two-phase flow theory. A custom LabVIEW application was utilized for data acquisition and control. During operation with refrigerant R-134a the system was shown to be robust under a range of heat loads from 100 W to 800 W. Operation was achieved with driving pressure differentials ranging from 3 bar to 12 bar and pulse frequencies ranging from 0.42 Hz to 0.08 Hz. An evolution of the PTL is also proposed that incorporates a novel, ejector-based pump-free refrigeration system. The design of the pulse refrigeration system (PRS) features valves at the outlet of two PTL-like boilers that are alternately actuated to direct pulses of refrigerant through an ejector. The design of the ejector was carried out using a one-dimensional model implemented in MATLAB that accounts for compressibility effects with NIST REFPROP vapor data sub-routines. The model enables the analysis of ejector performance in response to a transient pressure wave at the primary inlet.