Browsing by Author "Jamison, Kevin A"

Now showing 1 - 13 of 13
  • No Thumbnail Available
    Item
    Aerodynamic design of an electronics pod to maximise its carriage envelope on a fast-jet aircraft
    (2024-12) Du Rand, R; Jamison, Kevin A; Huyssen, Barbara
    The purpose of this paper is to reshape a fast-jet electronics pod’s external geometry to ensure compliance with aircraft pylon load limits across its carriage envelope while adhering to onboard system constraints and fitment specifications. Initial geometric layout determination used empirical methods. Performance approximation on the aircraft with added fairings and stabilising fin configurations was conducted using a panel code. Verification of loads was done using a full steady Reynolds-averaged Navier–Stokes solver, validated against published wind tunnel test data. Acceptable load envelope for the aircraft pylon was defined using two already-certified stores with known flight envelopes. Re-lofting the pod’s geometry enabled meeting all geometric and pylon load constraints. However, due to the pod's large size, re-lofting alone was not adequate to respect aircraft/pylon load limitations. A flight restriction was imposed on the aircraft’s roll rate to reduce yaw and roll moments within allowable limits. The geometry of an electronics pod was redesigned to maximise the permissible flight envelope on its carriage aircraft while respecting the safe carriage load limits determined for its store pylon. Aircraft carriage load constraints must be determined upfront when considering the design of fast-jet electronic pods. A process for determining the unknown load constraints of a carriage aircraft by analogy is presented, along with the process of tailoring the geometry of an electronics pod to respect aerodynamic load and geometric constraints.
  • Thumbnail Image
    Item
    Analysing the effects of rigid and flexible aircraft dynamics on the ejection of a large store
    (2011-09) Jamison, Kevin A
    The objectives of this presentation is to present the process followed at CSIR to evaluate the integration of the Katleho PGM with the BAE Hawk Mk120, to emphasise ejection dynamics and to share some of the experience and lessons learned with the project.
  • Thumbnail Image
    Item
    Automated analysis of aircraft configurations for safe separation enabled by quantitative grading of results; presentation
    (2012-09) Jamison, Kevin A; Heise, R
    When a new store is integrated with an aircraft, it is necessary to verify that it separates safely for all possible release and emergency jettison scenarios. A large number of separation analyses are required to comply with this requirement. This paper describes the development of an automated analysis process and software that can run a "script" of separation scenarios. A key enabler for this software is the development of a quantitative separation-grading algorithm that scores the outcome of each release against clearly defined criteria. The application of this software to the release/jettison dynamics of a typical aircraft/store is described.
  • No Thumbnail Available
    Item
    Decoupling store and parent aerodynamics for fast prediction of subsonic store trajectories
    (2024-09) Mthembu, N; Ndlovu, Hlamulo P; Ndebele, Bright B; Jamison, Kevin A; Zwane, Lindokuhle
    A method optimised for efficient prediction of subsonic store separation trajectories is described and demonstrated using a wind-tunnel test case. The FastTraj method uses a decoupled flow field approach where it is assumed that in most attached flow subsonic store separation scenarios the presence of the store has little impact on the perturbed flow field generated by the parent aircraft. The inviscid perturbed flow field of the parent aircraft is computed using computational fluid dynamics codes and is captured using a grid. The store aerodynamic model is generated elsewhere and Missile Datcom is used to segment the store model to approximate the effect of the perturbed flow field changing along the length of the store. The 6-DOF trajectory solver interpolates the aerodynamic grid from the parent aircraft to determine the local flow vector at each reference point on the segmented store, in addition to the local flow vector due to the motion of each segment. Good comparisons with the wind-tunnel data are achieved showing that the method’s speed is not at the expense of accuracy and that it is necessary to segment the store to achieve good results.
  • Thumbnail Image
    Item
    Developing the Inundu fast-jet electronics test and evaluation pod
    (2015-09) Jamison, Kevin A; Nkodi, T
    The development of the Inundu fast-jet electronics test and evaluation pod is described as a case study in the development of technology demonstrators. This pod is required to provide a “laboratory” environment for its electronics payload despite the rigors of being carried by fast-jet aircraft. This requirement, along with the need to be easily integrated with a wide variety of carriage aircraft resulted in a challenging development project.
  • Thumbnail Image
    Item
    Evaluating the release of a large store from the BAE Hawk Mk120
    (2010-11) Jamison, Kevin A; Heise, R
    The analysis of the release of a large store from the outboard pylon of the BAE Hawk Mk120 is described as a case study. The process adopted to address this challenge included using both the ARUV panel code and the CFD-FASTRAN Navier-Stokes Computational Fluid Dynamics (CFD) code where applicable to calculate the carriage loads; calculating the rigid and flexible structural dynamic responses from the ejection forces and using a three-component look-up table to model the loads on the store in free-flight through the aircraft flowfield computed by ARUV.
  • Thumbnail Image
    Item
    The first step towards decarbonized air mobility in South Africa: A hydrogen powered unmanned aerial vehicle
    (2022-11) Jamison, Kevin A; Naidoo, Purusha; Ramotsabi, Katleho
    The South African government is investing in the use of hydrogen fuel as a pathway towards decarbonising transport sectors. Hydrogen is likely to be a viable option for decarbonising air transport and it is being investigated intensively around the world. The merits of hydrogen as an air transport fuel relative to other alternatives are discussed. To localise expertise in hydrogen powered aviation in South Africa it was decided that a small hydrogen fuel cell powered unmanned aerial vehicle (UAV) would be developed as a first step. Once hydrogen powered flight is demonstrated at the UAV scale then the expertise gained can be scaled up to the general aviation sector and ultimately, commercial aviation. A concept of the UAV and its hydrogen fuel cell propulsion unit is presented and discussed.
  • Thumbnail Image
    Item
    Grid-mode transonic store separation analysis using modern design of experiments
    (ICAS, 2018-09) Jamison, Kevin A
    The analysis of the separation of a Precision Guided Munition (PGM) from many configurations of an advanced jet trainer was performed using aerodynamic data from wind-tunnel tests characterised using the grid method. As strong aerodynamic mutual interference is present due to transonic shockwaves between the wing of the aircraft and the tail of PGM the loads on the store changes significantly for different combinations of PGM position and orientation relative to the aircraft. This means that the grid method must sample a wide range of positions and orientations. If this is done in usual manner, the grid test matrix is large and costly. There is another method for efficiently characterising phenomena with a number of mutually interacting variables known as the Modern Design of Experiments (MDOE) which can significantly reduce the number of grid samples required. The possibility of developing the grid test matrix using the MDOE method is investigated using a simple panel code model. The correct approach to implement the MDOE grid method is identified and the relative interpolation errors are characterised. The application of the MDOE method to the trainer jet/PGM separation wind-tunnel test is described.
  • Thumbnail Image
    Item
    Quantitative grading of store separation trajectories
    (2017-09) Jamison, Kevin A; Rossouw, Pieter S; Miles, Elizna
    When a new store is integrated with an aircraft, it is necessary to verify that it separates safely for all possible release and emergency jettison scenarios. A large number of store separation analyses are required to comply with this requirement. This paper describes the development of an automated analysis process and software that can run a multitude of separation scenarios. A key enabler for this software is the development of a quantitative grading algorithm that scores the outcome of each release against clearly defined criteria. The separation grading algorithm eliminates the need for the analyst to assess each separate store separation scenario manually and subjectively by assigning scores based on a number of specific and measurable criteria. The scores obtained over a range of separation scenarios form a robust and quantitative basis for defining safe release envelopes for an aircraft/store combination and for motivating applicable pilot limitations. The application of this approach to the release/jettison dynamics of a typical aircraft/store configuration is described.
  • Thumbnail Image
    Item
    Quantitative grading of store separation trajectories
    (2017-09) Jamison, Kevin A; Rossouw, Pieter S; Miles, Elizna
    When a new store is integrated with an aircraft, it is necessary to verify that it separates safely for all possible release and emergency jettison scenarios. A large number of store separation analyses are required to comply with this requirement. This paper describes the development of an automated analysis process and software that can run a multitude of separation scenarios. A key enabler for this software is the development of a quantitative grading algorithm that scores the outcome of each release against clearly defined criteria. The separation grading algorithm eliminates the need for the analyst to assess each separate store separation scenario manually and subjectively by assigning scores based on a number of specific and measurable criteria. The scores obtained over a range of separation scenarios form a robust and quantitative basis for defining safe release envelopes for an aircraft/store combination and for motivating applicable pilot limitations. The application of this approach to the release/jettison dynamics of a typical aircraft/store configuration is described.
  • Thumbnail Image
    Item
    Selecting munition design features and operational concepts using a trade study supported by simulated operational scenarios
    (2021-09) Jamison, Kevin A; Roux, Jeanne M; Zwane, Lindokuhle
    A development of an existing munition aimed at an entirely new target set was planned. A trade study was performed to identify the key design features and employment concepts that generate the optimum outcomes in a demanding operational scenario. The trade study was configured as a Multi-Attribute Tradespace Exploration (MATE) using a trade study matrix that considers the key design and operational variables to be investigated. The baseline munition concept was parameterised such that design changes are described by those key variables. For each set of tradespace variables the baseline munition design was optimised to maximise its operational range while complying with constraints and meeting the design requirements. The characteristics of each optimised munition was determined for input into a simulation model of an operational scenario modelling the operational environment and the threat systems to determine the best performing munition solution. This paper outlines the implementation of the MATE approach and the lessons learned that can be incorporated in the broader systems engineering discipline.
  • Thumbnail Image
    Item
    Store separation trajectory predictions for maritime Search and Rescue (SAR)
    (Aerospace Research Central, 2017-06) Akroyd, G; Cenko, A; Piranian, A; Jamison, Kevin A; Malcolm, T
    The Australian Maritime Safety Authority (AMSA) plans to replace Dornier 328 turboprops with Bombardier Challenger 604 special mission jets modified for search and rescue (SAR). Similarly configured CL-604 Multi-Mission Aircraft are in service with the Royal Danish Air Force. Search and Rescue (SAR) Store Separation from Turbojet Aircraft. There are several store separation challenges posed by replacing a turboprop aircraft with a turbojet. For the 328 the rear cargo door used for store separation is well clear of the engine, Figure 1. For the 604 it’s just underneath the nacelle, Figure 2. In addition, the minim airspeed at which the 604 can release stores is higher, but sill subsonic. Unlike military aircraft, Sea Air Rescue has not used wind tunnel testing, Computational Fluid Dynamics (CFD) nor Six Degree-of-Freedom (SDOF) trajectory simulations prior to flight testing. This might have been since the released stores were relatively light weight, the airspeeds low, and incidental contact with the aircraft unlikely to cause significant damage at low airspeeds. This paper will describe how SDOF trajectory simulations might be used to reduce the cost and time required to safely complete a jet SAR flight test program.
  • Thumbnail Image
    Item
    A systems engineering framework for integrating stores with aircraft
    (2023-10) Jamison, Kevin A
    Military and some civilian aircraft need to carry stores to perform their mission. There is a huge diversity of carriage aircraft and types of stores ranging from missiles, drop tanks, space launchers, and rescue equipment. Adding stores to aircraft has a significant impact on the airworthiness of the carriage aircraft. Stores affect aircraft in multiple ways, making the integration of stores a complex multidisciplinary engineering problem that is often costly to resolve. The current regulatory and technical framework for store integration is reviewed. A systems engineering approach to store integration is presented where both aircraft and stores are designed from the outset to facilitate store integration. While some examples of this being done can be found, much still needs to be done to facilitate cost-effective store integration. Two case studies are presented and discussed showing the utility of this approach.