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Vikram Shyam

Publications and source records attributed to Vikram Shyam.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2023

Aviation 2072: Scenario Planning for Wicked Problems

The world is changing rapidly. And with it, so are the potential futures for humanity. Many of these potential futures pose hidden threats, while others offer new opportunities for aviation and the broader aerospace community. To mitigate these risks and capitalize on opportunities, organizations must work to deeply understand these potential future scenarios and uncover any underlying drivers. Organizations will be more equipped and informed when making strategic investment decisions by better understanding these threats, opportunities, and drivers . The future scenarios and their threats and opportunities described in this paper were identified through a series of extensive brainstorming workshops, collectively titled MADNESS (Mapping for Aviation Driven by Needs Emergence and Satiating Society). These workshops engaged NASA civil servants and contractors with diverse backgrounds through a facilitated process of future scenario development and critique. The participants were led through exercises focused on a time horizon spanning from 2022 to 2072 and on problems that aviation might solve and or create during this period. From the broad results, two patterns of critical uncertainty emerged: “availability” (scarcity versus abundance) and “transparency” (openness versus security and privacy). The successful iteration and ideation across the MADNESS workshops also suggests a repeatable mechanism for strategic risk exploration across a variety of NASA and industry stakeholders.

Mapping↗
NASA NTRS2021

NASA Framework for the Ethical Use of Artificial Intelligence (AI)

The NASA Framework for the Ethical Use of Artificial Intelligence (AI) provides six key principles to guide NASA's use of AI. The principles are NASA's AI must be 1. Fair, 2., Explainable and transparent, 3. Accountable, 4. Secure and safe, 5. Human-centric and societally beneficial, and 6. Scientifically and technically robust. The framework describes each ethical AI principle, and then applies that principle to NASA work. The framework also includes a list of questions practitioners should use to guide their AI work. Finally, the framework focuses on concrete, practical considerations for the next five - ten years, while also beginning to lay the foundation for longer-term disruptive change as human-level (or beyond) AI is created.

Artificial Intelligence↗
NASA NTRS2021

Topic Modeling Tool for PeTaL (Periodic Table of Life)

A topic modeling tool is constructed for the purpose of providing insights from biology to the engineer within the framework of PeTaL (Periodic Table of Life). The machine learning text mining tools–latent Dirichlet allocation (LDA) and nonnegative matrix factorization (NMF) with Kullback-Leibler (KL) divergence—are used to provide topic clusters to the user. Topic clusters are the underlying themes of a paper. For the text modeling problem, NMF-KL is the equivalent of probabilistic latent semantic analysis. Both LDA and NMF-KL are top-performing modeling tools. These tools are used to identify biological specimens relevant to the user. Various organisms solve a particular survival problem in nature differently. The topic clusters allow people without domain expertise to find these cross-topic themes in the body of documents and then branch out and examine papers whose target organisms solve the engineer’s problem. Abstracts from the Journal of Experimental Biology were used as input for the clustering tool in addition to a curated set of articles for validation. The tool is able to accept alternate input sources.

Machine learning↗
NASA NTRS2021

Bioinspired Honeycomb Core Design: An Experimental Study of the Role of Corner Radius, Coping, and Interface

The honeybee’s nest has inspired the design of engineering honeycomb core that primarily abstract the hexagonal cell shape and exploit its mass minimizing properties to construct lightweight panels. This work explored three additional design features that are part of the natural honeybee comb but have not been traditionally considered as design features of interest in honeycomb design: the radius at the corner of each cell, the coping at the top of the cell walls, and the interface between cell arrays. These features were first characterized in natural honeycomb using optical and X-ray techniques, and then incorporated into honeycomb core design, and fabricated using an additive manufacturing process. The honeycomb cores were then tested in out-of-plane compression and bending, and since all three design features added mass to the overall structure, all metrics were examined per unit mass to assess performance gains. The study concluded that the addition of an interface increases specific flexural modulus but has little benefit in out-of-plane compression; coping radius positively impacts specific flexural strength; but that the corner radius has no significant effect in bending, and actually is slightly detrimental for out-of-plane compression testing.

honeycomb↗
NASA NTRS2020

Strategic Perspectives on the Future of Systems Engineering at NASA

NASA’s Model-Based Systems Engineering (MBSE) Infusion and Modernization Initiative (MIAMI) chartered a strategy group comprising early to mid-career NASA subject matter experts with diverse experiences to look into the future of systems engineering at NASA. The purpose of the group was to provide a vision for the future state of systems engineering practices and to develop a strategic plan to enable the evolution of the art up to 20 years in the future. The group used a design thinking approach to gather ideas and obtained insight into current engineering processes and domain outlook by interviewing engineers of varying expertise and experiences who had worked on teams of different sizes for missions large and small. The group built a roadmap to highlight future needs, projected capabilities, and technology and competency gaps and developed a strategic plan to ensure the expedient introduction of these capabilities. The resulting strategic plan recommends capability development and workforce strategies and provides guidance for Agency-wide SE policy. Artifacts, details, and raw data from the strategy team’s work are contained in NASA/TM-20205002911/SUPPL, Strategic Perspectives on the Future of Systems Engineering at NASA: Supplemental Information: Appendixes A to K.

Anupa R Bajwa↗
NASA NTRSDate not supplied

Effects of Trailing Edge Thickness and Blade Loading Distribution on the Aerodynamic Performance of Simulated CMC Turbine Blades

The aerodynamic performance of three blade sets that represent the geometric manufacturing constraints of Ceramic Matrix Composite (CMC) blades was measured experimentally in a large-scale transonic turbine blade cascade. The trailing edge thicknesses of CMC blades are anticipated to be significantly larger than those of current state-of-the-art metallic blades. The blades tested in the current study had trailing edge thicknesses of 5%, 7%, and 9% relative to the blade axial chord. The three blade sets were designed with matching throat dimensions, so the blade loading distributions were varied to retain similar overall loading levels. Data were acquired at four Reynolds numbers, covering a factor of six range. All data were acquired at the design isentropic exit Mach number of 0.74. Measurements include blade loading and five-hole probe surveys at two downstream stations. The effects of inlet turbulence intensity were also quantified. Total pressure loss data were integrated to determine overall loss levels for each of the three measured blade passages. Excellent periodicity was noted. For low inlet turbulence levels, losses were surprisingly lower for the thickest trailing edge at low Reynolds numbers, but were highest at the maximum Reynolds number. In general, losses were found to scale well with Reynolds number, although front loading was found to significantly reduce the sensitivity of loss to Reynolds number. For high inlet turbulence intensity, losses were found to scale with trailing edge thickness as expected, and the Reynolds number sensitivity was reduced for all three blade sets. Loss levels at the highest Reynolds number were comparable at low and high inlet turbulence intensity levels.

Paul W Giel↗
NASA NTRSDate not supplied

Feasibility of Self Powered Actuation for Flow, Separation and Vibration Control

Gas turbine engines are anywhere from 40-50% efficient with a large amount of waste heat production. The primary focus of this work was to evaluate the feasibility of harvesting energy from sections of an imaginary but representative gas turbine engine that has large thermal gradients using thermoelectric generators (TEGs) and using the harvested energy locally for flow control using either plasma actuators or piezoelectric actuators. This work is a summary of a two- year NASA Center Innovation Fund Project from 2010 to 2012. The trade-off between thermoelectric harvesting and turbine blade surface temperature was studied to ensure that blade durability is not adversely impacted by embedding a low thermal conductivity TEG. Calculations show that at least 2-3 Watts can be harvested per blade depending on flow conditions and on the thermoelectric material chosen while maintaining metal temperatures below critical limits. BiTe and SiGe were considered as TEG materials although higher ZT materials are now in development. A circuit to convert the DC power output of the TEG to AC input for plasma actuation was fabricated and tested. Several novel plasma actuator configurations were also tested.

Thermoelectric↗
NASA NTRSDate not supplied

Effects of Trailing Edge Thickness and Blade Loading Distribution on the Aerodynamic Performance of Simulated CMC Turbine Blades

The aerodynamic performance of three blade sets that represent the geometric manufacturing constraints of Ceramic Matrix Composite (CMC) blades was measured experimentally in a large-scale transonic turbine blade cascade. The trailing edge thicknesses of CMC blades are anticipated to be significantly larger than those of current state-of-the-art metallic blades. The blades tested in the current study had trailing edge thicknesses of 5%, 7%, and 9% relative to the blade axial chord. The three blade sets were designed with matching throat dimensions, so the blade loading distributions were varied to retain similar overall loading levels. Data were acquired at four Reynolds numbers, covering a factor of six range. All data were acquired at the design isentropic exit Mach number of 0.74. Measurements include blade loading and five-hole probe surveys at two downstream stations. The effects of inlet turbulence intensity were also quantified. Total pressure loss data were integrated to determine overall loss levels for each of the three measured blade passages. Excellent periodicity was noted. For low inlet turbulence levels, losses were surprisingly lower for the thickest trailing edge at low Reynolds numbers, but were highest at the maximum Reynolds number. In general, losses were found to scale well with Reynolds number, although front loading was found to significantly reduce the sensitivity of loss to Reynolds number. For high inlet turbulence intensity, losses were found to scale with trailing edge thickness as expected, and the Reynolds number sensitivity was reduced for all three blade sets. Loss levels at the highest Reynolds number were comparable at low and high inlet turbulence intensity levels.

Turbine↗
NASA NTRSDate not supplied

Preliminary Study of Heat Pipe Turbine Vane Cooling in the NASA N+3 Reference Engine

This paper investigates the effects of implementing Heat Pipe Turbine Vane (HPTV) cooling in the NASA N+3 engine. The HPTV can be thought of as a heat pipe in the shape of a turbine vane, functioning as both an aerodynamic body and heat exchanger. The heat-absorbing section of the HPTV remains fixed in the vanes of the high pressure turbine (HPT), while the heat-rejecting section can be placed in any stage of the low pressure turbine (LPT) as well as the bypass stream. The optimal location of the condensing (heat-rejecting) section is shown to be in the bypass stream for both HPT stages. The thrust specific fuel consumption increased by 0.2%, which is mainly attributed to the elimination of air cooling in the second stage HPT vanes combined with the transfer of energy from the main gas path to elsewhere in the cycle. Air cooling is also eliminated in the first stage HPT vanes, but this cooling air is nonchargeable. A preliminary design is proposed and shown to demonstrate the desired performance and operates below all the heat flux limitations in the first stage HPT . The design in the second stage HPT exceeds a limiting phenomenon but is expected to be remedied by changing the working fluid.

Gas Turbine↗
NASA NTRSDate not supplied

Preliminary Study of Heat Pipe Turbine Vane Cooling in the NASA N+3 Reference Engine

This investigates the effects of implementing Heat Pipe Turbine Vane (HPTV) cooling in the NASA N+3 engine. The HPTV can be thought of as a heat pipe in the shape of a turbine vane, functioning as both an aerodynamic body and heat exchanger. The heat-absorbing section of the HPTV remains fixed in the vanes of the high pressure turbine (HPT), while the heat-rejecting section can be placed in any stage of the low pressure turbine (LPT) as well as the bypass stream. The optimal location of the condensing (heat-rejecting) section is shown to be in the bypass stream for both HPT stages. The thrust specific fuel consumption increased by 0.2%, which is mainly attributed to the elimination of air cooling in the second stage HPT vanes combined with the transfer of energy from the main gas path to elsewhere in the cycle. Air cooling is also eliminated in the first stage HPT vanes, but this cooling air is nonchargeable. A preliminary design is proposed and shown to demonstrate the desired performance and operates below all the heat flux limitations in the first stage HPT . The design in the second stage HPT exceeds a limiting phenomenon but is expected to be remedied by changing the working fluid.

Gas Turbine↗
NASA NTRSDate not supplied

Massless Exploration – Humans as a Solar System Species

A vision for exploration of the solar system in an earth independent manner is presented taking into account key drivers, challenges and future technological advances. This work was in response to requirements set by the NASA Advanced Exploration Systems (AES) Office. Planetary targets, key assumptions and approaches to utilizing non-terrestrial resources are presented. The mission was divided into four sprints. The first sprint aims at a settlement on Earth’s moon. The second sprint aims at establishing a Lagrangian point station near the moon. The third sprint leads to the colonization of Mars and its moons. The fourth and final sprint investigated the exploration of Callisto, a moon of Jupiter. Bio-inspired approaches to technology and processes were considered to ensure that the in-space habitats are Earth like. The conclusion based on exploring the four sprints is that it is feasible to colonize the solar system without relying on earth but this relies on critical technology development and investments in emerging areas.

In-situ resource utilization↗
NASA NTRSDate not supplied

Massless Exploration: Humans as a Solar System Species

A vision for exploration of the solar system in an earth independent manner is presented taking into account key drivers, challenges and future technological advances. This work was in response to requirements set by the NASA Advanced Exploration Systems (AES) Office. Planetary targets, key assumptions and approaches to utilizing non-terrestrial resources are presented. The mission was divided into four sprints. The first sprint aims at a settlement on Earth’s moon. The second sprint aims at establishing a Lagrangian point station near the moon. The third sprint leads to the colonization of Mars and its moons. The fourth and final sprint investigated the exploration of Callisto, a moon of Jupiter.. Bio-inspired approaches to technology and processes were considered to ensure that the in-space habitats are Earth like. The conclusion based on exploring the four sprints is that it is feasible to colonize the solar system without relying on earth but this relies on critical technology development and investments in emerging areas.

In-situ resource utilization↗
NASA NTRSDate not supplied

Embracing the fourth Industrial Revolution - Challenges, Opportunities and Path Forward for Propulsion

The aerospace industry is at a point where components are reaching design maturity and performance improvements are incremental. Aggressive goals to achieve sustainability and the threat of climate change necessitate a new paradigm. An artificial intelligence (AI) approach that enables revolutionary changes in system architecture, mission analysis and performance metrics is needed. The growing interest and development in the field of machine learning presents an opportunity to speed up by 10X or more the discovery, analysis and development of aerospace systems using artificial intelligence. Through IDEAS (Intelligent Design and Engineering of Aerospace Systems) we are embarking on a research and development effort that addresses this opportunity. The objective of IDEAS is to enable design of systems based on requirements. We discuss possible approaches to generating data, training models and applying them to near term applications. Results of recent workshops with industry, academia and other agencies to identify challenges to adopting AI and machine learning are presented.

Machine learning↗
NASA NTRSDate not supplied

Embracing the Fourth Industrial Revolution - Challenges, Opportunities and Path Forward for Propulsion

The aerospace industry is at a point where components are reaching design maturity and performance improvements are incremental. Aggressive goals to achieve sustainability and the threat of climate change necessitate a new paradigm. An artificial intelligence (AI) approach that enables revolutionary changes in system architecture, mission analysis and performance metrics is needed. The growing interest and development in the field of machine learning presents an opportunity to speed up by 10X or more the discovery, analysis and development of aerospace systems using artificial intelligence. Through IDEAS (Intelligent Design and Engineering of Aerospace Systems) we are embarking on a research and development effort that addresses this opportunity. The objective of IDEAS is to enable design of systems based on requirements. We discuss possible approaches to generating data, training models and applying them to near term applications. Results of recent workshops with industry, academia and other agencies to identify challenges to adopting AI and machine learning are presented.

Machine learning↗
NASA NTRSDate not supplied

A Future Beyond Convergence: Exploring Biocene - The Age of New Life

In a future age, the Biocene, our descendants will look back at the present. They will see evidence, in the geologic and electronic record, of anthropic climate change, conflict, and scarcity of resources. But they will also see the emergence of new life, the rebirth of human ingenuity and of empathy as we overcame the challenges that faced us through convergence and nature-inspired exploration.

Vikram Shyam↗
NASA NTRSDate not supplied

Cas Mapping – Helping Aviation Find Problems Worth Solving

The mapping process discovers trends, needs, and capabilities from interviews with diverse groups of people, data analytics tools, and from publications. These are analyzed in the context of future scenarios to uncover problem areas that have the highest possible impact on the broadest number of people while ensuring that we are prepared for the future.

Mapping↗
NASA NTRSDate not supplied

Discovery: Strategic Foresight – Helping Aviation Find Problems Worth Solving

Strategic foresight is used in the early stages of the CAS (Convergent Aeronautics Solutions) process. We discover trends, needs, and capabilities from interviews with diverse groups of people, data analytics tools, and from publications. These are analyzed in the context of future scenarios to uncover problem areas that have the highest possible impact on the broadest number of people while ensuring that we are prepared for the future.

Foresight Strategy Complex wicked↗