Organizational Unit:
Aerospace Systems Design Laboratory (ASDL)
Aerospace Systems Design Laboratory (ASDL)
Permanent Link
Research Organization Registry ID
Description
Previous Names
Parent Organization
Parent Organization
Organizational Unit
Includes Organization(s)
ArchiveSpace Name Record
Publication Search Results
Now showing
1 - 5 of 5
-
ItemConceptual Design of a BLI Propulsor Capturing Aero-Propulsive Coupling and Distortion Impacts(Georgia Institute of Technology, 2019) Pokhrel, Manish ; Shi, Mingxuan ; Ahuja, Jai ; Gladin, Jonathan ; Mavris, Dimitri N.Boundary Layer Ingestion (BLI) appears to be a promising solution to meet aggressive aviation fuel burn and environmental goals defined by NASA and other entities. Propulsion-airframe integration plays a critical role in BLI vehicle design given the strong coupling between the airframe and the propulsion system. Several studies have focused on flow field impacts on the propulsion system performance, but have ignored the effect of the propulsor on the flow field. Recent studies, however, have focused on both aspects, highlighting the need for capturing this interdisciplinary coupling. Multidisciplinary analyses (MDA), especially those involving CFD, are computationally expensive and are not suitable in the conceptual design of BLI propulsion systems. This paper aims to provide a less expensive approach by developing a parametric formulation for the effect of the propulsion system on the flow field, which can then be used in BLI propulsor conceptual design. This paper quantifies the sensitivity of the changes in the flow field due to the on-design and off-design parameters of the propulsion system. In addition, it also illustrates the difference in propulsion system design and performance when the throttle dependent effects on the flow field is captured, to the case where it is not. Distortion impacts on engine sizing and performance are also considered in this paper.
-
ItemSensitivity Analysis of Aero-Propulsive Coupling for Over-Wing-Nacelle Concepts(Georgia Institute of Technology, 2018) Berguin, Steven H. ; Renganathan, Sudharshan Ashwin ; Ahuja, Jai ; Chen, Mengzhen ; Tai, Jimmy C. M. ; Mavris, Dimitri N.A sensitivity analysis is performed to quantify the relative impact of perturbing a set of design variables representing an airplane configuration with Over-Wing Nacelles (OWN), operating at transonic cruise. The goal is to study the impact of perturbing the engine's XYZ position and power setting on installation drag, engine inlet pressure recovery, and lift curve characteristics. High- fidelity Reynolds Averaged Navier-Stokes (RANS) simulations of the Common Research Model (CRM) modified with powered, over-wing nacelles are performed and dominant main effects and interactions are identified. The most dominant effect was by far the engine's X position, but it was also found that podded OWN configurations exhibit statistically significant, aero-propulsive coupling. Specifically, certain engine locations cause changes in the flow-field that deteriorate inlet pressure recovery and, vice versa, a change in engine boundary conditions can affect installation drag. It is therefore recommended to simulate OWN concepts using a coupled MDA or MDAO approach to capture interdependencies between aerodynamics and propulsion.
-
ItemMultidisciplinary Analysis of Aero-Propulsive Coupling for the OWN Concept(Georgia Institute of Technology, 2018) Ahuja, Jai ; Renganathan, Sudharshan Ashwin ; Berguin, Steven ; Mavris, Dimitri N.The Over Wing Nacelle (OWN) concept enables the installation of turbofans with high bypass ratios for improved effciency in commercial transport vehicles, in addition to offering other advantages in the form of (i) mitigation of jet noise, (ii) foreign object damage avoidance and (iii) jet-powered lift. While these benefits can be offset by the large transonic drag rise, aerodynamic shape optimization of the wing and nacelle outer mold lines can help realize the full aerodynamic potential of the OWN concept. However, if coupling between the airframe aerodynamics and the propulsion system is strong, multidisciplinary optimization may need to be conducted. In this paper, the aerodynamics-propulsion coupling in the OWN concept is studied. A high fidelity Reynolds Averaged Navier Stokes (RANS) model along with a low fidelity engine thermodynamic cycle analysis model are used to represent the aerodynamic and propulsion systems respectively. The necessary coupling variables are identified and the coupled system is solved for disciplinary feasibility using the Fixed Point Iteration technique. The Common Research Model (CRM) wing and nacelle are used as the baseline geometry to carry out the study. The study reveals that for the OWN concept, aerodynamics-propulsion coupling is not significant enough to warrant multi-disciplinary shape optimization. While airframe aerodynamics has a strong effect on the propulsion system, the reverse interaction is weaker.
-
ItemA Comprehensive Energy Monitoring Environment for District Energy Grid Systems(Georgia Institute of Technology, 2017-07) Lewe, Jung-Ho ; Duncan, Scott J. ; Song, Kisun ; Oh, Sehwan ; Solano, David ; Yarbasi, Efe Y. ; Ahuja, Jai ; Johnston, Hunter B. ; Mavris, Dimitri N.By conducting active meter monitoring and performance analysis for the buildings and the plants at the main campus of the Georgia Institute of Technology, it is possible for campus facilities managers to achieve significant efficiency improvements. A key challenge, however, is gathering and making sense of the large volumes of utilities data. In response, a comprehensive web-based building and plant energy-monitoring environment is presented that collects data from multiple energy grids. From the gathered data, particular attention is given to heating, cooling, and ventilation to assess building and ultimately campus energy performance through various analytics. First, techniques for data gathering, organization, and filtering are described, followed by several novel metrics and ways of visualizing them via a comparative method. Data filtering and classification strategies have also been implemented into a framework capable of evaluating a fleet of buildings with respect to a data-driven or model-driven baseline. The resulting monitoring system is shown to reduce the number of variables that campus managers of campus utilities and facilities need to track and make it more obvious where energy efficiency opportunities exist across a large fleet of buildings. Implications and future extensions of the monitoring platform are discussed.
-
ItemEconomics of Advanced Thin-Haul Concepts and Operations(Georgia Institute of Technology, 2016) Harish, Anusha ; Perron, Christian ; Bavaro, Daniel ; Ahuja, Jai ; Ozcan, Melek D. ; Justin, Cedric Y. ; Briceno, Simon ; German, Brian J. ; Mavris, Dimitri N.The thin-haul commuter concept refers to an envisioned class of four to nine passenger aircraft operating very short flights and providing scheduled and on-demand air services from smaller airports. Its objective is to enhance regional mobility reach by combining the flexibility of automobile travel with the shorter commute times associated with air travel. To achieve economic viability, the thin-haul commuter concept must provide appreciable economic advantages when compared to current commuter aircraft. This may be achieved by increasing the revenue potential through innovative pricing and scheduling, while drastically reducing operating costs, in particular, energy, maintenance, and labor costs. These ambitious objectives require the infusion of new cutting edge technologies. The use of distributed electric propulsion is investigated to reduce both energy and maintenance expenditures. New avionics systems are considered to enable simplified operations and thus to reduce both labor and training costs. The purpose of this on-going research is to assess the viability of the thin-haul aviation concept by investigating both the operational and economic impact of introducing a fleet of distributed electric propulsion aircraft into the operations of a commuter airline. This paper presents the development of an integrated economics and operations model that incorporates preliminary estimates of a distributed electric propulsion vehicle performance as well as some aspects of typical commuter operator schedules. The model helps compare advanced electric vehicles with more conventional commuters, and therefore enables a preliminary assessment of the expected cost savings.