Joaquim R. R. A. Martins

Joaquim R. R. A. Martins
University of Michigan | U-M · Department of Aerospace Engineering

PhD

About

435
Publications
477,509
Reads
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19,584
Citations
Additional affiliations
September 2009 - August 2015
University of Michigan
Position
  • Professor (Associate)
November 2002 - August 2009
University of Toronto
Position
  • Associate Professor, Canada Research Chair in MDO (Tier 2)
September 1997 - October 2002
Stanford University
Position
  • Research Assistant
Education
September 1991 - June 1995
Independent Researcher
Independent Researcher
Field of study
  • Aeronautical Engineering

Publications

Publications (435)
Article
Full-text available
Multidisciplinary design optimization (MDO) is concerned with solving design problems involving coupled numerical models of complex engineering systems. While various MDO software frameworks exist, none of them take full advantage of state-of-the-art algorithms to solve coupled models efficiently. Furthermore, there is a need to facilitate the comp...
Article
Full-text available
The adjoint method is used for high-fidelity aerodynamic shape optimization and is an efficient approach for computing the derivatives of a function of interest with respect to a large number of design variables. Over the past few decades, various approaches have been used to implement the adjoint method in computational fluid dynamics solvers. How...
Book
Full-text available
Full text available at: https://mdobook.github.io/ Based on course-tested material, this rigorous yet accessible graduate textbook covers both fundamental and advanced optimization theory and algorithms. It covers a wide range of numerical methods and topics, including both gradient-based and gradient-free algorithms, multidisciplinary design opti...
Article
Full-text available
Interest in aircraft electrification and hydrogen fuel cells is driving demand for efficient waste heat management systems. Ultimately, most of the heat must be rejected to the freestream air. Ducted heat exchangers, also called ducted radiators, are the most common and effective way to do this. Engineers manually design ducted heat exchangers by a...
Article
Full-text available
based design optimization of stability constrained systems. AIAAJ, (In press). Abstract A partial differential equation (PDE) constrained design optimization problem usually optimizes a characteristic of a dynamical system around an equilibrium point. However , a commonly omitted constraint is the linear stability constraint at the equilibrium poin...
Article
Full-text available
Aviation's emissions are among the hardest to eliminate. There are a handful of solutions: battery-electric propulsion, hydrogen fuel cells, hydrogen combustion, and synthetic hydrocarbon fuel produced with carbon from the air. All of these solutions rely on renewable electricity, a resource that will be in short supply as other industries use it t...
Conference Paper
Full-text available
Propeller-wing interaction has been a topic of investigation since the dawn of aviation. Surprisingly, however, there are few published studies showing how changing a tractor propeller's vertical offset affects a trailing wing's lift and drag distributions. In this work, we investigate this for a rectangular wing with an inboard propeller using ste...
Article
Full-text available
Some novel aircraft concepts use unconventional propulsion technologies to reduce energy usage. Innovative technologies like distributed electric propulsion and boundary layer ingestion introduce new design challenges with airframe-propulsion integration. When designed in isolation, neither the airframe nor the propulsion system achieves maximum ef...
Conference Paper
Full-text available
Component intersections are a persistent challenge in aerodynamic design with the drag of a full configuration that is typically larger than that of its individual components. To remedy this, designers create fairings and fillets between the component surfaces to reduce this interference drag. These additions require iterative design and costly ana...
Article
Full-text available
When designing a vertical takeoff and landing (VTOL) aircraft, it is crucial to consider various operating conditions, including hover, wing-borne cruise, and transition. Takeoff transition and climb phases are critical for vehicle conceptual design because they drive the motor and battery sizing. However, these flight phases are often ignored or s...
Conference Paper
Full-text available
Multidisciplinary models are composed of numerous implicit systems that are solved in a coupled manner. A common challenge arises when an individual discipline’s Jacobian is non-invertible, which results in the coupled multidisciplinary model representing a saddle-point problem. In general, the small-scale multidisciplinary saddle-point problems ar...
Article
Full-text available
Airfoil design using numerical optimization has addressed the problem of minimizing drag for a given lift constraint for one or more flight conditions. However, designers often want to avoid separation at off-design conditions regardless of the drag. This paper develops a separation constraint formulation for airfoil shape optimization. We perform...
Article
Full-text available
The over-wing nacelle (OWN) configuration has the potential to improve on the conventional underwing nacelle (UWN) configuration by enabling higher bypass ratios and increasing noise shielding. To explore this potential, we perform coupled aeropropulsive design optimization to study the coupled analysis and the design trade-offs between aerodynamic...
Article
Full-text available
Composite materials provide greater freedom to tailor load-dependent deformations in lifting surfaces for improved hydrostructural efficiency across the operating envelope compared to metallic counterparts. For foils operating at high speeds, the trade-off between minimizing drag and avoiding cavitation and structural failure is a critical design c...
Article
Full-text available
Green hydrogen produced by electrolysis with renewable electricity can be used directly or in synthetic fuels (e-fuels) to decarbonize road, rail, marine, and air transportation. System inefficiencies during hydrogen or e-fuel production, storage, transportation, dispensing, and use lead to approximately 80–90% loss of the initial electrical energy...
Article
Full-text available
Accounting for propeller–wing interaction allows for the design of more efficient propeller aircraft through strategic propulsion integration. In this paper, the cruise drag of a wing with a propeller located in front of the wingtip is minimized using twist and airfoil-shape design variables. Reynolds-averaged Navier–Stokes computational fluid dyna...
Conference Paper
Full-text available
Well-designed hydrofoils improve ship resistance and seakeeping by lifting the hull above the water. With greater speeds come greater loads, and the two-way interaction of structural deflections of lifting surfaces on the hydrodynamics must be considered. Tailored structural anisotropy can improve hydrodynamic and structural efficiency of lifting s...
Article
Full-text available
The Surrogate Modeling Toolbox (SMT) is an open-source Python package that offers a collection of surrogate modeling methods, sampling techniques, and a set of sample problems. This paper presents SMT 2.0, a major new release of SMT that introduces significant upgrades and new features to the toolbox. This release adds the capability to handle mixe...
Article
Full-text available
Hydrogen aircraft have the potential to achieve more significant climate impact reductions at a lower cost than aircraft powered by biofuels or other drop-in sustainable aviation fuels. Nevertheless, even as a liquid, hydrogen requires four times more volume than kerosene to store the same energy. Companies and researchers have suggested that the b...
Conference Paper
Full-text available
The increasing flexibility of modern aircraft wings makes the consideration of aeroelasticity increasingly important in the earliest stages of the design process. In response to this need, the past decades have seen significant advances in the development of tools for the numerical optimization of aircraft wings considering aeroelastic interactions...
Conference Paper
Full-text available
Simultaneous design and trajectory optimization aims to find the best possible design of a dynamic engineering system, such as an aircraft, by considering the coupling between a physical system design and its trajectory. Multidisciplinary design optimization (MDO) fully considers this coupling and corresponding design trade-offs. This article discu...
Article
Hydrokinetic turbine (HKT) controllers are traditionally optimized after determining physical turbine variables. However, simultaneously varying controls and turbine shape by considering the interactions between the control space and the turbine shape can significantly enhance the system performance in contrast to the conventional sequential design...
Article
Full-text available
Aerodynamic shape optimization has become well established, with designers routinely performing wing and full aircraft optimizations with hundreds of geometric design variables. However, increased geometric design freedom increases optimization difficulty. These optimizations converge slowly, often taking hundreds of design iterations. In addition,...
Article
Full-text available
Hydrokinetic turbines extract kinetic energy from moving water to generate renewable electricity, thus contributing to sustainable energy production and reducing reliance on fossil fuels. It has been hypothesized that a duct can accelerate and condition the fluid flow passing the turbine blades, improving the overall energy extraction efficiency. H...
Article
Full-text available
Civil aviation provides an essential transportation network that connects the world and supports global economic growth. To maintain these benefits while meeting environmental goals, next-generation aircraft must have drastically reduced climate impacts. Hydrogen-powered aircraft have the potential to fly existing routes with no carbon emissions an...
Article
Full-text available
Geometry parameterization is a key challenge in shape optimization. Parameterizations must accurately capture the design intent and perform well in optimization. In multidisciplinary design optimization (MDO), the parameterization must additionally represent the shape consistently across each discipline. pyGeo is a geometry package for three-dimens...
Preprint
Full-text available
Hydrokinetic turbines extract kinetic energy from moving water to generate renewable electricity, thus contributing to sustainable energy production and reducing reliance on fossil fuels. It has been hypothesized that a duct can accelerate and condition the fluid flow passing the turbine blades, improving the overall energy extraction efficiency. H...
Article
Full-text available
Aircraft aerodynamic design often involves evaluating flow conditions that span low subsonic to transonic or even supersonic Mach numbers. Compressible flow solvers are a natural choice for such design problems, but these solvers suffer from reduced accuracy and efficiency at low Mach numbers. In addition, simulations with supersonic conditions can...
Conference Paper
Full-text available
See the newer peer-reviewed version: https://www.researchgate.net/publication/377749153
Conference Paper
Full-text available
Aerodynamic shape optimization is a valuable tool for aircraft design, but geometric constraints have had limited design freedom or have failed to capture spatial integration requirements in sufficient detail. Using a detailed representation of an aircraft's systems and payload geometries in a packaging constraint allows for more accurate and highe...
Conference Paper
Full-text available
Over-wing nacelle (OWN) configurations have two advantages over the traditional under-wing nacelle (UWN) configurations: 1. they make it easier to integrate high bypass ratio (BPR) and ultra-high BPR engines by removing ground clearance concerns, and 2. they significantly reduce noise because the wing blocks the noise of the fan and the jet. Despit...
Conference Paper
Full-text available
Three-surface configurations offer theoretical drag benefits over two-surface configurations, but the literature is unclear on what is the best configuration for a supersonic aircraft. This work uses trim-constrained drag minimization to compare the trim drag for three-surface, canard, and conventional variants of a supersonic transport aircraft. W...
Conference Paper
Full-text available
Multidisciplinary design optimization (MDO) plays a vital role in designing aircraft. Thus, the modularization of various disciplines is necessary to efficiently couple them in MDO or multidisciplinary design analysis (MDA). In this paper, we demonstrate how recent library extensions [1] lead to combining both the HPC ecosystem FlowSimulator, devel...
Article
Full-text available
Lightweight, high-aspect-ratio wings make aircraft more energy efficient thanks to their lower induced drag. Because such wings exhibit large deflections, design optimization based on linear flutter analysis of the wing undeformed shape is inadequate. To address this issue, we develop a framework for integrating a geometrically nonlinear flutter co...
Conference Paper
Full-text available
Over the past decade, advances in MDO have enabled the optimization of aircraft wings using high-fidelity simulations of their coupled aerodynamic and structural behavior. Using RANS CFD and detailed structural finite element wingbox models, the aerodynamic shape and internal structural sizing of a wing can be optimized concurrently to tailor the a...
Conference Paper
Full-text available
Advances in commercial propulsion technology led to the development of efficient high bypass ratio turbofan engines with larger overall pressure ratios and internal temperatures. Current trends suggest that geared ultra high bypass ratio turbofans are the next generation of commercial propulsion systems. Furthermore, the emphasis on decreasing emis...
Conference Paper
Full-text available
Many urban air mobility vehicle designs feature propellers integrated with fuselage, wings, and other appendages. These vehicle designs are based on complex configurations with novel propulsion systems and flight technology. The tightly coupled nature of the systems in these vehicles and the novel technologies within them create opportunities for v...
Conference Paper
Full-text available
To improve performance and reduce fuel consumption, we must address tightly connected aeropropulsive effects in the development of new and existing propulsion technologies. Aero-propulsive design optimization considers the multidisciplinary coupled interactions between aerodynamics, thermodynamics, and geometry. Mixed-fidelity aeropropulsive method...
Preprint
Full-text available
The Surrogate Modeling Toolbox (SMT) is an open-source Python package that offers a collection of surrogate modeling methods, sampling techniques, and a set of sample problems. This paper presents SMT 2.0, a major new release of SMT that introduces significant upgrades and new features to the toolbox. This release adds the capability to handle mixe...
Conference Paper
Full-text available
Composite marine lifting surfaces are increasing in popularity over metallic counterparts due to favorable material properties compared to traditional metallic structures such as high strength-to-weight ratio and tailorable anisotropy. However, these lightweight materials have different unsteady fluid-structure interaction phenomena that denser met...
Article
Full-text available
When designing aircraft, avoiding dynamic aeroelastic instabilities such as flutter is a key requirement. One way to meet this requirement is to use a multidisciplinary design optimization subject to a flutter constraint. Flutter-constrained design optimizations have used geometrically linear detailed models, which do not accurately predict flutter...
Article
Full-text available
Off-design constraints are essential in practical aerodynamic shape optimization. Physics-based data-driven modeling has shown to be a feasible way to formulate generalizable off-design constraints. However, two issues hinder the adoption of this approach: inadequate physical mechanism studies and the requirement of massive training data. To addres...
Article
Full-text available
Previous work on hydrostructural optimization of composite lifting surfaces primarily focused on using an equivalent single-layer unidirectional composite. However, composite lifting surfaces are often constructed with a large number of layers of fiber-reinforced polymers to sustain various loading conditions, prevent crack propagation, and improve...
Preprint
Full-text available
Reducing the cost of energy from wind power is a critical step towards decarbonizing the electric grid and mitigating climate change effects. Computational models are crucial in understanding the complex, multiphysics interactions of modern, highly flexible wind turbine rotors. When coupled with numerical optimization, such models provide an effici...
Article
Full-text available
The conceptual design process of aircraft starts by deciding the representative mission requirements, followed by optimization of design variables to satisfy the given requirements. However, the appropriate mission requirements are not obvious, especially when designing package delivery unmanned aerial vehicles (UAVs; also called drones). The UAVs...
Presentation
Full-text available
This is a presentation summarizing the paper with the same title available here: https://www.researchgate.net/publication/366157885_Hydrogen-Powered_Aircraft_Fundamental_Concepts_Key_Technologies_and_Environmental_Impacts
Preprint
Control co-design (CCD) explores physical and control design spaces simultaneously to optimize a system's performance. A commonly used CCD framework aims to achieve open-loop optimal control (OLOC) trajectory while optimizing the physical design variables subject to constraints on control and design parameters. In this study, in contrast with the c...
Conference Paper
Please see the newer peer-reviewed version: https://www.researchgate.net/publication/384302581
Conference Paper
Full-text available
Multiple propulsors on distributed electric propulsion (DEP) aircraft drastically widen the design space of these aircraft. The present paper presents the initial development of a prototype multidisciplinary design optimization (MDO) framework for DEP aircraft that accounts for flight controls and aerodynamics. The framework was applied to the NASA...
Conference Paper
Full-text available
Many urban air mobility vehicle designs are under development, featuring configurations that combine propellers with wings, tails, fuselage, and additional appendages. These complex geometries introduce physical phenomena such as propeller-wing and propeller-propeller interactions. Understanding these phenomena and optimizing a vehicle design consi...
Conference Paper
Full-text available
See journal version of this paper: https://www.researchgate.net/publication/384397436_Coupled_Aeropropulsive_Design_Optimization_of_an_Over-Wing_Nacelle