Related Experiment Video
Updated: Jan 11, 2026
07:58
Improving the Combustion Performance of a Hybrid Rocket Engine using a Novel Fuel Grain with a Nested Helical Structure
Published on: January 18, 2021
6.4K
Heating rate gradient drives mesostructural dynamics in solid propellant under nonequilibrium conditions
Zhi Jiang1, Tianhao Wang1, Weichen Sheng1
1School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Summary
Rapid heating rates, not bulk temperature, control material changes under extreme conditions. This study reveals how local heating dictates void formation and fragmentation in composites, impacting ignition and combustion.
Area of Science:
- Materials Science
- Chemical Engineering
- Physics
Background:
- Heterogeneous composite materials undergo rapid structural evolution under extreme thermal conditions, impacting aerospace and structural applications.
- Current experimental methods cannot observe dynamic structural changes under realistic nonequilibrium thermal fronts.
- Existing theoretical models often assume equilibrium conditions, limiting their predictive accuracy.
Purpose of the Study:
- To develop and demonstrate a novel experimental system for observing mesoscale structural evolution in composite materials under controlled, rapid, nonequilibrium heating.
- To investigate the influence of local heating rates on void formation, fragmentation, and ignition pathways.
- To provide experimental validation for theoretical models of material behavior under extreme thermal loads.
Main Methods:
- Development of a gradiated fast-heating system with precise control over heating rate gradients (>20 °C/s) in submillimeter regions.
- Integration of sequential synchrotron X-ray tomography and radiography for direct visualization of internal structural evolution.
- Analysis of microsecond-to-millisecond timescale transformations from pyrolysis through ignition to burnout.
Main Results:
- Local heating rates, not bulk temperatures, were identified as the primary drivers of void formation and fragmentation dynamics.
- High local heating rates led to rapid void nucleation and reticulated porous network formation in the binder phase, occurring significantly faster than interfacial void evolution.
- Heterogeneous component interactions fragmented the metallic network, creating ignition hotspots that controlled combustion initiation and propagation.
Conclusions:
- Mesoscale structural evolution in composite materials under extreme nonequilibrium heating is critically dependent on local heating rates and kinetic processes.
- The developed experimental approach enables direct observation of complex transformation pathways, advancing the understanding of material behavior under extreme conditions.
- Findings provide crucial data for validating and improving theoretical models for predicting composite material performance in demanding applications.
More Related Videos
10:52Conducting Elevated Temperature Normal and Combined Pressure-Shear Plate Impact Experiments Via a Breech-end Sabot Heater System
Published on: August 7, 2018
8.8K
06:26Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
7.5K
Related Concept Videos
01:14Mechanisms of Heat Transfer I
5.9K
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
5.9K
01:14Mechanisms of Heat Transfer
1.6K
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
1.6K
01:12Rocket Propulsion In Empty Space - II
3.4K
The motion of a rocket is governed by the conservation of momentum principle. A rocket's momentum changes by the same amount (with the opposite sign) as the ejected gases. As time goes by, the rocket's mass (which includes the mass of the remaining fuel) continuously decreases, and its velocity increases. Therefore, the principle of conservation of momentum is used to explain the dynamics of a rocket's motion. The ideal rocket equation gives the change in velocity that a rocket...
3.4K
01:20Mechanisms of Heat Transfer II
4.2K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
4.2K
01:13Rocket Propulsion in Empty Space - I
3.7K
The driving force for the motion of any vehicle is friction, but in the case of rocket propulsion in space, the friction force is not present. The motion of a rocket changes its velocity (and hence its momentum) by ejecting burned fuel gases, thus causing it to accelerate in the direction opposite to the velocity of the ejected fuel. In this situation, the mass and velocity of the rocket constantly change along with the total mass of ejected gases. Due to conservation of momentum, the...
3.7K
01:19Mechanism of heat transfer
1.8K
Understanding heat transfer mechanisms is essential for understanding how our bodies maintain balance in different environmental conditions. When the environment is thermoneutral, the body is in a state of balance, neither using nor releasing energy to maintain its core temperature. However, when the environment is not thermoneutral, the body employs four heat transfer mechanisms to maintain homeostasis: conduction, convection, evaporation, and radiation. These mechanisms facilitate heat...
1.8K