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Articles 2251 - 2280 of 11196
Full-Text Articles in Aerospace Engineering
A Framework For The Automatic Identification Of Optimized Yield Surface Parameters, Kevin Hanekom
A Framework For The Automatic Identification Of Optimized Yield Surface Parameters, Kevin Hanekom
Honors Undergraduate Theses
Advanced engineering materials are designed to display tensile-compressive asymmetry (TCA) and anisotropy to provide unique attributes to critical components necessary in the hot section of turbines. The never-ending chase for higher efficiencies, and with them, higher temperature gradients, intrinsically leads to more and more of these complex materials, like single crystal turbine blades, embedded within the turbine environment. Mathematical models, known as yield criteria, allow engineers to visualize the mechanical behavior of these materials in various orientations under complex loading. Yield criteria are dependent on three key items in determination of their governing parameters: material test data, mathematical constraints, and …
An Evaluation Of Thermocouple Reconstruction Techniques, Derek Brauneis
An Evaluation Of Thermocouple Reconstruction Techniques, Derek Brauneis
Electronic Theses and Dissertations, 2020-2023
Temperature measurements can be difficult to obtain across many different harsh environments such as engine combustion chambers, engine exhaust temperatures, and explosion fireballs. While there are alternate methods to measure fluid temperature such as laser measurements, acoustic measurements, and camera imaging techniques, these methods can often be expensive, difficult to implement, and not able to see within the environment. Thermocouples are popular sensors because they are cheap and easy to implement across a wide range of applications and can measure temperature in areas where other methods cannot reach or see. However, while these sensors are very popular and versatile, they …
The Impacts Of Advanced Avionics On Degraded Visual Environments, Sultan Naseeb Harib Fairouz Mubarak, Anju Anna Jacob Dr
The Impacts Of Advanced Avionics On Degraded Visual Environments, Sultan Naseeb Harib Fairouz Mubarak, Anju Anna Jacob Dr
International Journal of Aviation, Aeronautics, and Aerospace
Degraded visual environments (DVE) such as brownout, sand storms, and night conditions are responsible for accidents and hence losses in the aviation industry. There is a need to develop avionic systems to support pilots when they encounter environmental conditions that compromise their visual capacity. This report discusses the effects of DVEs on aviation, expounds on the advanced avionic systems available and further elaborates how these systems are implemented in countering DVE conditions. The report recommends on how advanced avionics systems have been and are being implemented in aircrafts to support decisions made by pilots flying under degraded visual environments.
Accuracy Assessment Of The Ebee Using Rtk And Ppk Corrections Methods As A Function Of Distance To A Gnss Base Station, Joseph Cerreta, David Thirtyacre, Peter Miller, Scott S. Burgess, William J. Austin
Accuracy Assessment Of The Ebee Using Rtk And Ppk Corrections Methods As A Function Of Distance To A Gnss Base Station, Joseph Cerreta, David Thirtyacre, Peter Miller, Scott S. Burgess, William J. Austin
International Journal of Aviation, Aeronautics, and Aerospace
The use of unmanned aircraft systems to collect data for photogrammetry models has grown significantly in recent years. The accuracy of a photogrammetric model can depend on image georeferencing. The distance from a reference base station can affect the accuracy of the results. Positioning corrections data relies on precise timing measurements of satellite signals. The signals travel through the Earth's atmosphere, which introduces errors due to ionospheric and tropospheric delays. The aim of this research was to examine the eBee X and its global GNSS accuracy by comparing the RTK and PPK methods at different base station distances in photogrammetry …
Stochastic Optimization To Reduce Aircraft Taxi-In Time At Igia, New Delhi, Rajib Das, Saileswar Ghosh, Rajendra Desai, Pijus Kanti Bhuin, Stuti Agarwal
Stochastic Optimization To Reduce Aircraft Taxi-In Time At Igia, New Delhi, Rajib Das, Saileswar Ghosh, Rajendra Desai, Pijus Kanti Bhuin, Stuti Agarwal
International Journal of Aviation, Aeronautics, and Aerospace
Since there is an uncertainty in the arrival times of flights, pre-scheduled allocation of runways and stands and the subsequent first-come-first-served treatment results in a sub-optimal allocation of runways and stands, this is the prime reason for the unusual delays in taxi-in times at IGIA, New Delhi.
We simulated the arrival pattern of aircraft and utilized stochastic optimization to arrive at the best runway-stands allocation for a day. Optimization is done using a GRG Non-Linear algorithm in the Frontline Systems Analytic Solver platform. We applied this model to eight representative scenarios of two different days. Our results show that without …
Simplified Mass And Inertial Estimates For Aircraft With Components Of Constant Density, Benjamin C. Moulton, Douglas F. Hunsaker
Simplified Mass And Inertial Estimates For Aircraft With Components Of Constant Density, Benjamin C. Moulton, Douglas F. Hunsaker
Mechanical and Aerospace Engineering Student Publications and Presentations
Aircraft mass and inertial properties are required for predicting the dynamics and handling qualities of aircraft. However, such properties can be difficult to estimate since these depend on the external shape and internal structure, systems, and mass distributions within the airframe. Mass and inertial properties of aircraft are often predicted using computer-aided design software, or measured using various experimental techniques. The present paper presents a method for quickly predicting the mass and inertial properties of complete aircraft consisting of components of constant density. Although the assumption of constant density may appear limiting, the method presented in this paper can be …
Auto-Ignition Characteristics Of Hydrogen Enriched Natural Gas For Gas Turbine Applications, Christopher T. Loving
Auto-Ignition Characteristics Of Hydrogen Enriched Natural Gas For Gas Turbine Applications, Christopher T. Loving
Graduate Thesis and Dissertation 2023-2024
A successful transition to clean energy hinges on meeting the world's growing energy demand while reducing greenhouse gas emissions. Achieving this will require significant growth in electricity generation from clean and carbon-free energy sources. Several energy providers have already begun the transition from traditional carbon-based fuels to cleaner alternatives, such as hydrogen and hydrogen enriched natural gas. However, there are still many technical challenges that must be addressed when applying these fuels in gas turbines. The application of hydrogen or hydrogen/natural gas blends to advanced class gas turbines, which have higher operating pressures and temperatures has raised concerns about the …
Rotorcraft Lander Fixed To A Descending Capsule Backshell, Corey Zucker
Rotorcraft Lander Fixed To A Descending Capsule Backshell, Corey Zucker
Electronic Theses and Dissertations, 2020-2023
NASA is financing a mission to study the surface of Titan, Saturn's largest moon, to investigate the terrain, chemical compositions, and potential for existent life. This mission is an exciting advancement from Mars Ingenuity, because the quadrotor lander, Dragonfly, will be the first of its kind with four coaxial rotors. Upon entry into Titan, and at near surface atmospheric conditions, Dragonfly will exit a parachute supported backshell that has shed its protective heatshield. The aerodynamics of this state are significant in comprehending the dynamics of the overall system for successful deployment into powered flight. The studies presented here examine the …
Hypersonic Aero-Optic Measurements In A High-Pressure Shock Tube, Jonathan P. Mcgaunn
Hypersonic Aero-Optic Measurements In A High-Pressure Shock Tube, Jonathan P. Mcgaunn
Graduate Thesis and Dissertation 2023-2024
The high-pressure shock tube facility (HiPER-STAR) at the University of Central Florida (UCF) is analyzed experimentally to demonstrate the practicality of hypersonic aero-optical testing in an impulse facility without the use of an expansion nozzle or acceleration tube. The investigation analyses driver gas blending with helium and hydrogen to raise the speed of sound ratio in an attempt to increase the Mach number for aero-optics testing. HiPER-STAR has a unique ability to withstand pressures up to 1000 atm and run in a double diaphragm configuration allowing for a significant pressure differential to be created between the driver and driven sections. …
Thermal Management Strategies For Hypersonic Flight: Supercritical Co2 Jet Impingement Cooling Investigation For Leading Edge, Manoj Prabakar Sargunaraj
Thermal Management Strategies For Hypersonic Flight: Supercritical Co2 Jet Impingement Cooling Investigation For Leading Edge, Manoj Prabakar Sargunaraj
Graduate Thesis and Dissertation 2023-2024
This study addresses the critical need for effective thermal management in hypersonic vehicles facing intense heat at their leading edge due to high enthalpy flow. The objective is to propose an active impingement cooling system that ensures the structural stability and performance of these vehicles. This dissertation presents an in-depth exploration of the numerical simulations conducted on the hypersonic leading edge, focusing on a 3mm radius with active cooling utilizing supercritical carbon dioxide (sCO2) as the coolant. The research incorporates conjugate simulations that merge external hypersonic flow and sCO2 active cooling. Utilizing a thermodynamic non-equilibrium two-temperature model and various chemical …
Efficacy, Durability And Design Of A Bucket Wheel Excavator For Icy Lunar Regolith, Austin Lohsandt
Efficacy, Durability And Design Of A Bucket Wheel Excavator For Icy Lunar Regolith, Austin Lohsandt
Electronic Theses and Dissertations
This research project focused on the design and testing of a prototype bucket wheel excavator developed for NASA's Break the Ice Lunar Challenge, which sought innovative ideas for lunar excavation. Several attempts have been made by other universities and private industries to create systems that can successfully excavate simulated frozen regolith, however, few have been successful. The chosen excavation technology employed a bucket wheel concept inspired by large open-pit mining machines, modified to incorporate grinding nubs for pulverizing lunar simulant material. The goals included proving the viability of a bucket wheel excavator for lunar excavation, exploring grinding nubs, conducting durability …
Air Traffic Management Principles: A Case Study On How To Create A Sustainable System, Eva Maleviti
Air Traffic Management Principles: A Case Study On How To Create A Sustainable System, Eva Maleviti
Publications
BEYOND ENVIRONMENTAL SUSTAINABILITY
- Emissions, SAF, CORSIA, Design
- Economic growth and development
- Sustainability should go beyond environment
- Non-technology approaches for sustainability and Net-Zero targets
- What about social sustainability and people?
In the total share of aviation emissions (1GT CO2) 3% is 3Mt CO2. Small share but very significant contribution.
Fostering Safer Evacuations Aboard Commercial Aircraft: A Problem-Solution Analysis, George Skinner
Fostering Safer Evacuations Aboard Commercial Aircraft: A Problem-Solution Analysis, George Skinner
Student Works
This problem-solution analysis analyzes factors impeding safe and orderly evacuations for the Federal Aviation Administration (FAA). Although rarely used, evacuation procedures are critical for keeping passengers safe during emergency situations. However, there are flaws in these procedures and many factors exist which make aircraft evacuations slow and dangerous. During a situation in which time is of the essence, these impediments can make the difference between an incident and a fatal accident. This report focuses on data gathered through full-scale evacuation simulations and analyzes shortcomings and strengths in three accidents. This information is then compared to current procedures and regulations that …
Solar Sailing Adaptive Control Using Integral Concurrent Learning For Solar Flux Estimation, Luis Enrique Mendoza Zambrano, Riccardo Bevilacqua
Solar Sailing Adaptive Control Using Integral Concurrent Learning For Solar Flux Estimation, Luis Enrique Mendoza Zambrano, Riccardo Bevilacqua
Student Works
In the interest of exploiting natural forces for propellant-less spacecraft missions, this investigation proposes an adaptive control strategy to account for unknown parameters in the dynamic modeling of a reflectivity-controlled solar sail spacecraft. A Lyapunov-based control law along with integral concurrent learning is suggested to accomplish and prove global exponential tracking of the estimated parameters and states of interest, without satisfying the common persistence of excitation condition, which in most nonlinear systems cannot be guaranteed a priori. This involves estimating the solar flux or irradiance from the Sun to account for uncertainty and variation over time in this value. To …
Experimental Validation Of Inertia Parameters And Attitude Estimation Of Uncooperative Space Targets Using Solid State Lidar, Alessia Nocerino, Roberto Opromolla, Giancarmine Fasano, Michele Grassi, Spencer John, Hancheol Cho, Riccardo Bevilacqua
Experimental Validation Of Inertia Parameters And Attitude Estimation Of Uncooperative Space Targets Using Solid State Lidar, Alessia Nocerino, Roberto Opromolla, Giancarmine Fasano, Michele Grassi, Spencer John, Hancheol Cho, Riccardo Bevilacqua
Student Works
This paper presents an experimental activity aimed at assessing performance of techniques for inertia and attitude parameters estimation of an uncooperative but known space target. The adopted experimental set-up includes a scaled-down 3D printed satellite mock-up, a spherical air bearing and a low-cost solid-state LIDAR. The experimental facility also comprises a motion capture system to obtain a benchmark of the pose (position and attitude) parameters and an ad-hoc designed passive balancing system to keep the centre of mass as close as possible to the centre of rotation. The LIDAR-based 3D point clouds, collected while the target rotates on the spherical …
Distributed Optimization For Rank-Constrained Semidefinite Programs, Chaoying Pei, Sixiong You, Chuangchuang Sun, Ran Dai
Distributed Optimization For Rank-Constrained Semidefinite Programs, Chaoying Pei, Sixiong You, Chuangchuang Sun, Ran Dai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
This letter develops a distributed optimization framework for solving the rank-constrained semidefinite programs (RCSPs). Since the rank constraint is non-convex and discontinuous, solving an optimization problem with rank constraints is NP-hard and notoriously time-consuming, especially for large-scale RCSPs. In the proposed approach, by decomposing an unknown matrix into a set of submatrices with much smaller sizes, the rank constraint on the original matrix is equivalently transformed into a set of constraints on the decomposed submatrices. The distributed framework allows parallel computation of subproblems while requiring coordination among them to satisfy the coupled constraints. As the scale of every subproblem solved …
Convolutional-Neural-Network-Based Des-Level Aerodynamic Flow Field Generation From Urans Data, John P. Romano, Oktay Baysal, Alec C. Brodeur
Convolutional-Neural-Network-Based Des-Level Aerodynamic Flow Field Generation From Urans Data, John P. Romano, Oktay Baysal, Alec C. Brodeur
Mechanical & Aerospace Engineering Faculty Publications
The present paper culminates several investigations into the use of convolutional neural networks (CNNs) as a post-processing step to improve the accuracy of unsteady Reynolds-averaged Navier–Stokes (URANS) simulations for subsonic flows over airfoils at low angles of attack. Time-averaged detached eddy simulation (DES)-generated flow fields serve as the target data for creating and training CNN models. CNN post-processing generates flow-field data comparable to DES resolution, but after using only URANS-level resources and properly training CNN models. This document outlines the underlying theory and progress toward the goal of improving URANS simulations by looking at flow predictions for a class of …
Flight Software Development For A University-Class Microsatellite Mission, Yumeka Nagano
Flight Software Development For A University-Class Microsatellite Mission, Yumeka Nagano
Masters Theses
"The purpose of this research is to present the software development process used by the Command and Data Handling (C&DH) subsystem as a part of a microsatellite mission underway at the Missouri University of Science and Technology. The mission's objective is to evaluate the performance of an innovative cold gas propulsion system for use in formation flying applications and the incorporation of a stereoscopic imaging sensor used to measure the satellite pair's relative position and velocity vectors in real time. C&DH uses a Raspberry Pi 3 Model B as the flight computer running a Linux environment, and the flight code …
Implementing Effective University - Level Small Satellite Assembly, Integration, And Testing Procedures, Tyler Patrick Hoover
Implementing Effective University - Level Small Satellite Assembly, Integration, And Testing Procedures, Tyler Patrick Hoover
Masters Theses
"As applications for satellite assets grow within government and commercial spheres, demand for aerospace engineers and related technicians has pushed universities to develop graduates with relevant knowledge in the field. As such, universities began to grow university satellite programs to give members hands-on experience and a background of working on satellite systems before entering the workforce.
The M-SAT team at Missouri University of Science and Technology, along with contributions and assistance from the Air Force Research Laboratory and NASA, are progressing their first satellite mission through assembly, integration, and testing (AIT) development. This document serves to give a background into …
Numerical Study Of The Time-Periodic Electroosmotic Flow Of Viscoelastic Fluid Through A Short Constriction Microchannel, Jianyu Ji, Shizhi Qian, Armani Marie Parker, Xiaoyu Zhang
Numerical Study Of The Time-Periodic Electroosmotic Flow Of Viscoelastic Fluid Through A Short Constriction Microchannel, Jianyu Ji, Shizhi Qian, Armani Marie Parker, Xiaoyu Zhang
Mechanical & Aerospace Engineering Faculty Publications
Electroosmotic flow (EOF) is of utmost significance due to its numerous practical uses in controlling flow at micro/nanoscales. In the present study, the time-periodic EOF of a viscoelastic fluid is statistically analyzed using a short 10:1 constriction microfluidic channel joining two reservoirs on either side. The flow is modeled using the Oldroyd-B (OB) model and the Poisson-Boltzmann model. The EOF of a highly concentrated polyacrylamide (PAA) aqueous solution is investigated under the combined effects of an alternating current (AC) electric field and a direct current (DC) electric field. Power-law degradation is visible in the energy spectra of the velocity fluctuations …
A Numerical Analysis Of Shock Angles From Inward Turning Axisymmetric Flows, William L. Hilal
A Numerical Analysis Of Shock Angles From Inward Turning Axisymmetric Flows, William L. Hilal
Honors Undergraduate Theses
Detonation-based propulsion systems are known for their high efficiency and energy release when compared to deflagrative systems, making them an ideal candidate in hypersonic propulsion applications. One such engine is the Oblique Detonation Wave (ODW) engine, which has a similar architecture to traditional scramjets but shortens the combustor and isolator to an anchored ODW after fuel injection.
Previous research has focused on using a two-dimensional wedge to induce an ODW while limiting total losses through the combustor. In this configuration, a two-dimensional wedge-based architecture entails a rectangular duct, limiting potential inlet design and increasing overall skin friction. However, an inward-turning …
An Optimization Study Of Small-Scale Propeller Blade, Fahad M. Nabid
An Optimization Study Of Small-Scale Propeller Blade, Fahad M. Nabid
Honors Undergraduate Theses
This research paper aims to investigate the optimization of smaller propeller blades to achieve maximum efficiency by studying the effect of the twist angle on reducing drag, increasing thrust, and preventing rapid wear on the blade. Inefficient propellers consume a significant amount of energy, particularly during low-speed flights. The low Reynolds number regime challenges aviation engineers to design propellers with the highest possible efficiency to minimize energy losses. The primary objective of this thesis is to optimize smaller propeller blade shapes to enable them to produce maximum efficiency. The advanced ratio of a propeller blade heavily influences the blade's performance …
Hypersonic Scramjet Inlet Development For Variable Mach Number Flows, Zachary P. White
Hypersonic Scramjet Inlet Development For Variable Mach Number Flows, Zachary P. White
Honors Undergraduate Theses
Hypersonic propulsion has become an increasingly important research field over the past fifty years, and subsequent interest in propulsion systems utilizing supersonic combustion has emerged. Air-breathing engines are desirable for such applications as hypersonic flight vehicles would not need to carry an oxidizer. Therefore, hypersonic air-breathing propulsion systems require an inlet with high mass capture and compressive efficiency. The present work seeks to outline the development and validation of a novel design tool for producing air inlet designs for hypersonic vehicles at variable flight conditions. A Busemann inlet was chosen for its high compressive efficiency, geometric flexibility, and existing experimental …
The Development Of Computational Models For Melting-Solidification Applications Using The Volume-Of-Fluid Method, Brendon Cavainolo
The Development Of Computational Models For Melting-Solidification Applications Using The Volume-Of-Fluid Method, Brendon Cavainolo
Electronic Theses and Dissertations, 2020-2023
Fluids-related issues in the Aerospace industry are often multiphase in scope. Numerical modeling, such as computational fluid dynamics, is used to describe these problems, as they are difficult or impossible to describe analytically. This research uses computational fluid dynamics to describe multiphase problems related to melting-solidification and particle impingement. Firstly, a numerical model was established that uses the Volume-of-Fluid method to resolve a melting/solidifying particle. This model was verified against experiments and simplified analytical models, and a mesh independence study was done to ensure the results were independent of the mesh sizing. Next, the model was applied to two separate …
A Computational Fluid Dynamic Analysis Of Oxyacetylene Combustion Flow For Use In Material Response Boundary Conditions, Craig Meade
Theses and Dissertations--Mechanical and Aerospace Engineering
Oxyacetylene torches are used in the aerospace industry and research to test thermal protection system materials (TPS) due to their high flame temperatures and high heat flux capabilities. The purpose of this work is to determine a combustion model to accurately simulate the high temperature flow of an oxyacetylene torch. The flow conditions around a sample material can then be used as boundary conditions when modeling TPS material response. Two separate combustion models with equilibrium chemistry were investigated using ANSYS Fluent™; the Eddy-Dissipation Model, and the Partially Premixed model.The results of this study are compared to existing experiments for validation.
Stratospheric Glider Measurements Of Atmospheric Parameters, Anisa Haghighi
Stratospheric Glider Measurements Of Atmospheric Parameters, Anisa Haghighi
Theses and Dissertations--Mechanical and Aerospace Engineering
In June 2021 a series of high altitude flights were conducted in Spaceport America, NM, using a balloon launched Uncrewed Aircraft System (UAS) to assess its capability to conduct measurements of various atmospheric properties and study turbulence in the troposphere and lower stratosphere. This UAS descends using an automated flight trajectory. The instruments aboard included a NASA-developed infrasonic microphone to evaluate its remote turbulence detection capabilities and a five-hole probe capable of measuring the in situ wind vector. Also on board were temperature, humidity and wind profile sensors. This document focuses on the atmospheric properties measured at high altitudes, the …
Impact Of Spallation And Internal Radiation On Fibrous Ablative Materials, Raghava Sai Chaitanya Davuluri
Impact Of Spallation And Internal Radiation On Fibrous Ablative Materials, Raghava Sai Chaitanya Davuluri
Theses and Dissertations--Mechanical and Aerospace Engineering
Space vehicles are equipped with Thermal Protection Systems (TPS) that encounter high heat rates and protect the payload while entering a planetary atmosphere. For most missions that interest NASA, ablative materials are used as TPS. These materials undergo several mass and energy transfer mechanisms to absorb intense heat. The size and construction of the TPS are based on the composition of the planetary atmosphere and the impact of various ablative mechanisms on the flow field and the material. Therefore, it is essential to quantify the rates of different ablative phenomena to model TPS accurately. In this work, the impact of …
Precision Meteorological Prediction Employing A Data-Driven, Adaptive, Real-Time (Dart) Approach, Sujit Sinha
Precision Meteorological Prediction Employing A Data-Driven, Adaptive, Real-Time (Dart) Approach, Sujit Sinha
Theses and Dissertations--Mechanical and Aerospace Engineering
The objective of this research is to improve precision meteorological prediction, benefiting both uncrewed aerial vehicle (UAV) operations by avoiding hazardous flight conditions and tracking contaminant or toxic clouds caused by incidents, accidents, or fires. The operational concept is to collect meteorological observations from instruments mounted on a swarm of UAVs, telemeter the data to a weather simulation model, revise the predicted solution by adapting the flow field to the observations, and then transmit the updated forecast to appropriate personnel as well as to the guidance system of UAVs for repositioning to the next set of most beneficial measurements. While …
Detonability Of A Rotating Detonation Combustor Seeded With Carbon/Hydrocarbon Particles At Fringe Operating Conditions, Matthew Hopwood
Detonability Of A Rotating Detonation Combustor Seeded With Carbon/Hydrocarbon Particles At Fringe Operating Conditions, Matthew Hopwood
Electronic Theses and Dissertations, 2020-2023
The Rotating Detonation Combustor (RDC) has, in recent years, been a subject of great interest in the pressure-gain combustion research community. Researchers have been investigating the RDC as a potential improvement over current combustors in today's turbomachinery-based power generation systems. With the theoretical efficiency boost that detonations provide over deflagrating combustors, RDCs have the promise to be a next step in fuel/cost savings in the power generation industry. One mode of research to push an RDCs capabilities is the potential use of combustible carbon/hydrocarbon solid particles in addition to liquid or gaseous fuels. These particles are a source of high …
Heat Release And Flame Scale Effects On Turbulence Dynamics In Confined Premixed Flows, Max Fortin
Heat Release And Flame Scale Effects On Turbulence Dynamics In Confined Premixed Flows, Max Fortin
Electronic Theses and Dissertations, 2020-2023
As industry transitions to a net-zero carbon future, turbulent premixed combustion will remain an integral process for power generating gas turbines and are also desired for aviation engines due to their ability to minimize pollutant emissions. However, accurately predicting the behavior of a turbulent reacting flow field remains a challenge. To better understand the dynamics of premixed reacting flows, this study experimentally investigates the evolution of turbulence in a high-speed bluff-body combustor. The combustor is operated across a range of equivalence ratios from 0.7-1 to quantify the role of heat release and flame scales on the evolution of turbulence as …