About

Phillip J. Ansell is an Associate Professor in the Department of Aerospace Engineering at the University of Illinois at Urbana-Champaign. He holds a BS in Aerospace Engineering from The Pennsylvania State University (2008), and both an MS (2010) and a Ph.D. (2013) in Aerospace Engineering from the University of Illinois at Urbana-Champaign. His research interests encompass applied aerodynamics, sustainable aviation, distributed propulsion, flow control, aircraft electrification, atmospheric flight sciences, and unsteady aerodynamics. Ansell has contributed to the field through his work on aerospace systems design and simulation, experimental fluid mechanics, and flow control, with a focus on advancing sustainable aviation technologies. He has authored or co-authored numerous articles in reputable journals, exploring topics such as hydrogen fuel cell aircraft, zero-emission aviation ecosystems, aeropropulsive shape optimization, and high-lift airfoil design. His research aims to develop innovative solutions for environmentally sustainable aircraft and to enhance understanding of unsteady aerodynamics and flow control mechanisms in aerospace applications.

Research topics

• Engineering
• Aerospace engineering
• Electrical engineering
• Environmental science
• Chemistry
• Waste management
• Automotive engineering
• Operations research
• Ecology
• Operations management
• Aeronautics

Selected publications

• Impact of Technology Maturation on Advanced Hydrogen Fuel Cell Aircraft

  Journal of Aircraft · 2026-05-01

  articleSenior author

  Hydrogen fuel cells are a promising power source for commercial aircraft, emitting only water vapor in flight. However, advances in fuel cell stack technology and supporting systems are required before large-scale integration into aircraft is feasible. This study evaluates how the maturation of key technologies influences aircraft performance metrics, including weight, range, and energy efficiency. Parameterized models are constructed for fuel cell stacks, air and thermal management systems, propulsive components, and aircraft aerodynamics. Performance projections for hydrogen-powered integrated propulsion systems (IPS) are quantified for 2020, 2035, and 2050 technology levels using parameters compiled from previous studies. Further analysis investigates retrofitting four conventional aircraft with IPS power plants. While IPS power plants remain heavier than turbofans even at the 2050 technology level, their enhanced energy efficiency enables aircraft-level energy intensity reduction, with narrow-body aircraft demonstrating substantial improvements by 2035. Hydrogen volume constrains the range of short-range aircraft at the 2020 technology level and limits long-range aircraft at all technology levels. Enablers of energy-efficient hydrogen flight include an IPS specific power above [Formula: see text] and a 0.7 hydrogen fuel tank gravimetric efficiency. By 2050, all aircraft variants demonstrate marked reductions in energy intensity, underscoring the long-term sustainability potential of hydrogen fuel cell aircraft.

  PublisherDOI

• A Theoretical Foundation, Methodology, and Framework for Aircraft Life Cycle Sustainability Assessment

  2026-01-08

  articleSenior author

  This work documents the development, theory, methodology, and goals of an aircraft life cycle family of models for aviation sustainability assessment. This family of models estimates sustainability outcomes from the inputs and outputs of an aircraft program throughout its life cycle. The stages of an aircraft program considered are design, manufacturing, operations, maintenance, and end of life. Unlike existing tools, this framework integrates quantitative engineering models with qualitative sustainability knowledge across five interconnected domains: engineering, policy, economics, society, and environment. The framework employs a life cycle model that covers design, manufacturing, operations, MRO, and end of life, with iterative feedback loops to capture emergent sustainability effects such as the economic rebound phenomena (Jevons Paradox). A qualitative case study using the Boeing 737-200 demonstrates the framework's abilities to to capture sustainability metrics and reveal how aircraft can produce vastly different sustainability outcomes due to differences in operation. This paper closes with a discussion of challenges within sustainability integration to aircraft design.

  PublisherDOI

• Parametric Flow Analysis of a Curvature-Continuous Aeropropulsive Wing

  2026-01-08

  articleSenior author

  Advanced propulsion-airframe integration is a technology that has been increasingly utilized in the design of advanced sustainable aircraft systems. Embedding propulsive devices into aerodynamic surfaces -- aeropropulsion -- can provide performance benefits, but this approach also adds significant complexity to aerodynamic surface design. Many past publications have demonstrated various workflows to parameterize, analyze, and optimize these aeropropulsive aircraft, but most of them have not focused on detailed blending surfaces between propulsive devices and wings or fuselages. For this purpose, an end-to-end workflow from planform design to aeropropulsive simulation is detailed and demonstrated for a transonic wing with a bank of three propulsive devices embedded in the lower surface. A new, lightweight CAD package written with this application in mind was used for the design and parameterization of the geometry. A comparison of the effect of various blending parameters on the flow indicated that both an extension in the extrusion distance of the pressure recovery surfaces between the propulsors and an increase in the amplitude of the geometric waves joining the nacelle bodies mitigated or eliminated the shock waves present in the inviscid flow field. The compressible flow interactions across the wing-nacelle surfaces demonstrated significant complexity, with variations in shock features produced with changing angles of attack. Such an observation demonstrates an opportunity of using the current geometry parameterization framework with multi-point optimization strategies.

  PublisherDOI

• Technology exploration of zero-emission regional aircraft: Why, what, when and how?

  Progress in Aerospace Sciences · 2026-01-01

  articleOpen access

  The paper focuses on the exploration and comparison of zero-emission technology strategies for regional aircraft. While significant progress is made on the development of technologies, systems and aircraft configurations, major challenges and uncertainties mean that various strategies are considered but are difficult to compare as they rely on different technologies, metrics, requirements, maturity levels and sustainability targets. A novel, holistic approach that captures inter-dependencies, synergies and combined impact of technologies is developed to evaluate the feasibility of such aircraft over 2 horizons, quantify performance and emissions through various phases of the life cycle, establish technology bottlenecks and required step changes and classify developments in terms of impact and risk. For at least 30 passengers at 300 nmi, significant advances are required for fuel cells (2 kW/kg), electric machines (13 kW/kg), power distribution ( > 1.5 kVolts), and thermal management systems (3.5 kW/kg and 3.5 kW/kW). These will lead to major mission level ( + 90%) and lifecycle energy penalties (up to + 177%) with a carbon intensity level of 6.5 kg CO2 /kg H2 (ex. blue, turquoise, green hydrogen) required to breakeven current CO 2 levels. Step changes including superconductivity and high temperature fuel cells, along with aircraft mass and drag reductions are required to increase capacity to pax > 40 and 800 nmi, and achieve energy reductions against existing designs. The energy density of batteries and the need of gas turbines to meet diversion and hold requirements limit full electric variants to 30 passengers at 200 nmi with 480 Wh/kg battery energy density but they can offer an exceptional energy per passenger benefit ( ∼ 40% reduction) against current aircraft.

  PublisherDOI

• Life Cycle Analysis of Power-to-X Aviation Fuels

  2026-01-08

  articleSenior author

  The life cycle analysis of Power-to-X aviation fuels, including liquid hydrogen, liquefied natural gas, and liquefied petroleum gas, is presented in this paper. A combination of semi-empirical and empirical methods is utilized to calculate the resource consumption and greenhouse gas emissions across the entire well-to-tank pathway, including the production, distribution, storage, and delivery processes. The reactor performance is modeled using experimental results from the literature, including results from latest high-selectivity hydrogenation studies. The present study also considers two liquefaction scenarios: local liquefaction at the airport with onsite facilities, and non-local liquefaction requiring long-distance transport and a secondary liquefaction stage. A sensitivity study is also conducted to examine the influence of the key model parameters on the overall life cycle analysis results.

  PublisherDOI

• Technoeconomic and Energy Life Cycle Assessments of Wind Energy Systems for Regional Hybrid Electric Aircraft

  2026-01-08

  articleSenior author

  This paper compares energy cost and life cycle CO2 equivalent (CO2e) emissions of regional hybrid electric aircraft against conventional regional aircraft supported by jet fuel. Various regional hybrid-electric aircraft were considered, having a range of battery specific energies and degrees of hybridization. The energy cost and life cycle emissions for these aircraft were evaluated across three electricity supply scenarios: 1) electricity is sourced from an existing grid, 2) electricity is sourced from a correspondingly sized wind turbine and battery energy storage system (BESS), or 3) electricity is sourced from a combination of an existing grid and a sized wind energy system. To evaluate infrastructure impacts, an airport site is identified with high wind potential resulting in favorable wind turbine infrastructure size, cost, and CO2e emissions. The results of the study show the impact of hybrid electric aircraft battery specific energy and degree of hybridization on energy costs. As the battery specific energy increases in value, energy consumption and energy cost reduces. The breakeven energy cost for hybrid electric aircraft with electricity provided by a wind turbine and BESS is calculated relative to conventional aircraft. The breakeven cost reduces when the associated renewable energy infrastructure is sized to support lower charge rates or more flights per day. When evaluating hybrid electric aircraft energy CO2e emissions, the total CO2e emissions are heavily influenced by grid emission characteristics. When evaluating the case where hybrid electric aircraft are supported by sized wind energy infrastructure alone, emission reductions are seen compared to the conventional aircraft for all hybrid electric aircraft and electricity demand characteristics considered.

  PublisherDOI

• Potential Flow Framework for Design of Aeropropulsive Geometries with Powered Wakes

  Journal of Aircraft · 2026-03-29

  articleSenior author

  Broadening interest by the aeronautics community in distributed electric propulsion systems has revealed a need for design and analysis methods capable of resolving the two-way coupling of aeropropulsive systems. A 2D, inviscid, and incompressible scheme to investigate the performance of these systems is described, which builds on prior, extensively used developments toward modeling airfoils in potential flow. The scheme incorporates a vortex panel method for multiple lifting geometries and iteratively solves for the circulation distribution and position of a powered jet wake that emanates downstream from a propulsive device, bounding the propulsive streamtube. The scheme is capable of resolving both the upper and lower wake boundaries, as well as the thickness of the surface elements. The code was mathematically verified, as well as experimentally validated with data from a quasi-two-dimensional wind tunnel model with an integrated nozzle. Experimentally acquired velocity field data were used to calculate the circulation distribution in the powered wake shear layers downstream of the model. These results, together with pressure distributions, are compared to code predictions. The numerical scheme demonstrated good computational characteristics and provided accurate predictions of an aeropropulsive system’s performance when the scheme’s assumptions were shown to hold throughout the flow domain of study.

  PublisherDOI

• Airfoil Decambering for Gust Load Alleviation Using a Bi-stable Hinge

  2026-01-08

  article

  Wing sections with bistable hinges outfitted on trailing edge flaps provide a promising means for passively rejecting gust loads on an aircraft. This study found that there exists a two-way coupling between the aerodynamic loads experienced by the airfoil and the deflection of the bistable hinge and corresponding flap. The current work demonstrates how the energy wells of a bistable hinge system can be configured to introduce decambering of the airfoil when stall limits are approached. By expressing the interdependent coupling between the global flow state and the hinge material properties, a bistable hinge can be designed to produce snap-through transitions when prescribed aerodynamic states are reached. The efficacy of this bistable hinge integration strategy is shown in an experimental campaign, where passive alleviation of aerodynamic loads are produced in the vicinity of airfoil stall limits.

  PublisherDOI

• Non-Uniform Rational B-Spline Parameterization for Aerodynamic Shape Optimization

  2026-01-08

  articleSenior author

  Through this study, direct geometric parameterization framework is introduced, using non-uniform rational B-splines (NURBS), for aerodynamic shape optimization. A NURBS geometry generation suite is integrated with the high-fidelity SU2 multiphysics simulation and design software and IPOPT to handle high-dimensional, nonlinear design problems. The framework is evaluated for two-dimensional aerodynamic shape optimization with NURBS curves using the standardized RAE 2822 test case from the AIAA Aerodynamic Design Optimization Discussion Group. A three-dimensional implementation is also introduced using NURBS surfaces applied to aerodynamic shape optimization of a Blended Wing Body (BWB) concept. The study compares the NURBS framework with a conventional free-form deformation (FFD) method, keeping all other conditions equivalent. Different optimization barrier update schemes are demonstrated for both the NURBS and FFD optimization. The NURBS parameterization shows a drag reduction of 45.5% compared to FFD's 34.45% on the RAE 2822 case when subject to lift, pitching-moment, and area constraints. Initial iterations of the BWB aerodynamic shape optimization using the NURBS framework demonstrate a drag reduction of 7.47% compared to FFD's 0.53% for a fixed lift constraint. These results reveal the superior performance of NURBS for these shape optimization problems for identical bound constraints imposed on the design variables.

  PublisherDOI

• Surface Impingement Dynamics of Ducted and Unducted Propulsors

  2025-01-03

  articleSenior author

  The current program considers the ground plane interactions of three different propulsive devices of equivalent thrust and streamtube diameter. These propulsors include a ducted fan device with standard stators, a ducted fan device that retains the fan-induced swirl, and an open propeller. These devices permit an isolated comparison of the influences of jet axial velocity, tangential (swirl) velocity, and wake vortex features for propulsion systems used in VTOL aircraft operations. For all three propulsors, thrust and torque data were collected over a range of ground plane states, as well as flow field data using stereoscopic particle image velocimetry. Test stand data shows a clear connection between the swirling flow influence and the ground effect impact on performance. The presence of swirling flow in the wake allows the ground surface to act as a stator by turning swirling momentum into axial momentum for added thrust production. Inclined surface angles create a "downhill" flow divergence preference in response to a favorable pressure gradient; this is exaggerated by swirling flow promoting counterclockwise rotation in the flow, which results in more flow directed "downhill".

  PublisherDOI

Frequent coauthors

• Georgi Hristov

  18 shared

• Kiruba S. Haran

  16 shared

• Joseph W. Zimmerman

  CU Aerospace (United States)

  14 shared

• David L. Carroll

  14 shared

• Michael Bragg

  12 shared

• Constantinos Minas

  12 shared

• Ernst Wolfgang Stautner

  12 shared

• Armando R. Garcia

  Boeing (United States)

  11 shared

Labs

• The Grainger College of EngineeringPI