Thermal Control Design Research Articles

The space quadrant and intelligent occlusion calculation methods for the external heat flux of China space Station

In the thermal control design of spacecraft and the study of its infrared radiation characteristics, the influence of external heat flux must be considered emphatically. In order to solve the complex space occlusion problem of China Space Station, the centroid ontology coordinate system is first defined as the reference coordinate system in this paper. Then, the space quadrant and intelligent occlusion calculation methods are proposed. The former is mainly to solve the shielding of the external heat flux of spacecraft body. The latter is to solve the shielding of the external heat flux of large external hangings. The results show that the maximum occlusion time is up to 6.5 min and the maximum occlusion difference is about 0.7 in the same quadrant at different solar incident angles. Moreover, if the shielding of external hangings is not considered, the time is more than 15 min when the external heat flux difference exceeds 4000 W in the sunlight area, and the maximum difference is about 6000 W. Meaningfully, the space quadrant and intelligent occlusion calculation methods proposed in this paper can effectively solve most of the occlusion problems and is suitable for various spacecraft.

Temperature-dependent phonon anharmonicity and thermal transport in CuInTe2

The Cu-based chalcopyrite compounds are good thermoelectrics for waste heat harvesting, partially due to the dramatic reduction of the thermal conductivity above Debye temperature, whereas the mechanism of this drop is still elusive. By Raman measurements from 7 to 780 K, we have investigated the anharmonicity of the phonon modes ${\mathrm{B}}_{2}^{1}, {\mathrm{A}}_{1}$, and ${\mathrm{B}}_{2}^{3}$ in ${\mathrm{CuInTe}}_{2}$. The fourth-order anharmonicity of ${\mathrm{B}}_{2}^{1}$ and ${\mathrm{B}}_{2}^{3}$ modes is greatly enhanced with increasing temperature and becomes dominant above 400 K. The phonon dynamics is calculated from 10 to 800 K. The fourth-order anharmonicity is predominant over the third-order ones for the phonon modes at low ($<70\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$) and high ($>130\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$) frequency domains, confirmed by the enhanced weighted phase space and scattering rate of the four-phonon processes above 300 K. The phonon avoided-crossing is found to take place around 40 ${\mathrm{cm}}^{\ensuremath{-}1}$ between the lowest-optical mode and acoustic modes. Counting on the fourth-order phonon anharmonicity, the calculated lattice thermal conductivity agrees well with experiment. The results unveil that the dramatic thermal conductivity reduction, about 83% from 300 to 800 K, originates from the enhanced four-phonon process. Our insights on the thermal transport mechanisms might benefit the materials design of thermoelectrics and thermal control.

Application of Transfer Function in Predicting the Temperature Field of Space Equipment Under Periodic External Heat Flow

The temperature state of outer space devices is influenced by the heat flow outside the space. Although traditional numerical simulation analysis methods are highly accurate, they are time-consuming and not conducive for researchers to quickly assess the effects of external heat flow variations and are difficult to apply to program optimization codes that require large-scale iterative calculations or to codes for on-board temperature control chips. This paper presents an analytical algorithm for heat transfer problems: The transfer function method is applied to the thermal control analysis of outer space equipment with a small computational effort and a simple and straightforward computational procedure. Although this analytical approach only considers a limited set of influencing parameters and the precision of the calculation cannot be compared with numerical methods, it can be applied to the early prediction of internal temperature changes caused by heat flow changes outside the modification of outer space devices, embedded in the optimization code of a design solution, or integrated into the code of an on-board temperature control chip with minimum computational effort. In general, the transfer function method is not suitable for solving the radiation term, whereas this paper excludes the radiation term from the time delay calculation based on the small time scale of the radiation term and solves the time delay of the internal temperature relative to the external surface temperature directly, whereas the amplitude decay of the internal temperature change relative to the external surface temperature fluctuation is solved by the steady-state method based on the long period of the external heat flow change. The practicality of the transfer function method in the design of thermal control of external space devices is evidenced by comparing the computational results with those of commercial software and experimental results.

Investigation on thermal model updating of Alpha Magnetic Spectrometer in orbit based on Kriging meta-modeling

The purpose of the update of the space instrument thermal model is to make adjustments to the model parameters to maintain the consistency between the temperature simulation consequences and the experimental data, which is essential for thermal control design. This study proposed an approach of combining Kriging meta-modeling and Genetic Algorithm (GA) instead of direct iteration to update the Alpha Magnetic Spectrometer (AMS) thermal model, which significantly boosts the updating efficiency. Firstly, the importance ranking of the thermal model parameters affecting its temperature response is determined by the parameter sensitivity analysis. The Kriging surrogate model of the AMS simulation temperature is then established by training samples from sensitive parameters using Latin Hypercube Sampling (LHS) method, and its reliability is demonstrated by the maximum error of 0.86 °C in contrast to thermal model results at other specific model parameter values. Based on above information, a set of optimal parameters are eventually generated to update the original AMS thermal model by GA with the improvement of the temperature prediction accuracy up to 13.96%. The current work provides an efficient and accurate approach for thermal model optimization and thermal control design of the space-borne instruments.

Passive Thermal Control Design Methods, Analysis, Comparison, and Evaluation for Micro and Nanosatellites Carrying Infrared Imager

Advancements in satellite technologies are increasing the power density of electronics and payloads. When the power consumption increases within a limited volume, waste heat generation also increases and this necessitates a proper and efficient thermal management system. Mostly, micro and nanosatellites use passive thermal control methods because of the low cost, no additional power requirement, ease of implementation, and better thermal performance. Passive methods lack the ability to meet certain thermal requirements on larger and smaller satellite platforms. This work numerically studies the performance of some of the passive thermal control techniques such as thermal straps, surface coatings, multi-layer insulation (MLI), and radiators for a 6U small satellite configuration carrying a mid-wave infrared (MWIR) payload whose temperature needs to be cooled down to 100K. Infrared (IR) imagers require low temperature, and the level of cooling is entirely dependent on the infrared wavelengths. These instruments are used for various applications including Earth observations, defence, and imaging at IR wavelengths. To achieve these low temperatures on such instruments, a micro-cryocooler is considered in this study. Most of the higher heat dissipating elements in the satellite are mounted to a heat exchanger plate, which is thermally coupled to an external radiator using thermal straps and heat pipes. The effects of the radiator size, orbital inclinations, space environments, satellite attitude with respect to the sun, and surface coatings are discussed elaborately for a 6U satellite configuration.

Extrusion and thermal control design of an on-orbit 3D printing platform

On-orbit manufacturing can reduce the cost and time needed by space exploration missions because in-situ maintenance activities can be achieved without the need for additional launches. Furthermore, recent developments in materials science in terms of better mechanical and thermal performance have allowed this application to become a potential reality. However, the deployment of on-orbit manufacturing presents several challenges, including the lack of convective heat transfer and human intervention. This paper proposes an on-orbit 3D printing device capable of operating at a temperature up to 400 °C in the vacuum environment. To validate its feasibility for on-orbit manufacturing, we designed four extruders with different characteristics. We investigated the temperature profiles across the extruders under the vacuum condition through a heat transfer model. Based on the thermal analysis, a thermal control method, which combines the Proportion (P) and Fuzzy Proportion and Integration (Fuzzy PI) strategies, is designed to regulate the 3D printing device operation. With the extrusion rate of 8654.6 mm3 /h and the printing temperature at 400 °C, the melting and solidification status of the PEEK (Polyether ether ketone) material is verified.

Design and verification of the thermal control system for the Zhurong rover

<p indent="0mm">The conditions of low temperature, weak sunlight, and low-density atmosphere on Mars pose severe challenges to the thermal control design and verification of the Zhurong rover. The thermal control system adopts the idea of broadening sources of incoming energy and reducing energy expenditure. This is accomplished by an energy conversion and storage system based on in-situ solar energy use combined with a nano-aerogel insulation system, which solves the problems of energy supply and heat loss without a nuclear source. The thermal design has been verified by thermal analysis simulations. Low-pressure static thermal balance tests, low-pressure atmosphere thermal balance tests, and thermal control product performance tests were carried out to validate the thermal model. The testing was successful, and the thermal control verification problem, caused by the difficulty of comprehensively simulating the thermal environment on Mars, was solved. The successful design and full verification of the thermal control system laid the foundation for the spacecraft to complete its mission.

Thermal Control Design and Packaging for Surface Acoustic Wave Devices in Acoustofluidics.

This article presents a thermal control design method for a surface acoustic wave (SAW) device. We designed a heat-dissipation structure and packaging scheme to solve three key issues observed in SAW devices using anisotropic crystals as piezoelectric substrates in acoustofluidics (e.g., lithium niobate): SAW chip cracking caused by thermal stress, SAW chip cracking caused by mismatched thermal expansion coefficients of the packaging materials, and enhancement of the structural strength and stability of the SAW chip. This study establishes the physical model of the designed structure and the relationship between the steady-state working temperature and the physical properties of the material. By comparing these physical properties and numerical calculations, we identified nanosilver adhesive as the most effective bonding material between the SAW chip and the heat sink. In addition to designing and fabricating, we also evaluated our SAW devices experimentally. The results not only confirmed that the abovementioned three key problems were solved but also demonstrated the significant enhancement of the stability of the SAW device.

Thermal control design and simulation of micro star sensor

Thermal control design and simulation of micro star sensor

Thermal Control Design and Validated for MEO Navigation Satellites

Thermal Control Design and Validated for MEO Navigation Satellites

Design of Joint Thermal Control for Space Manipulator

Design of Joint Thermal Control for Space Manipulator

Small Satellite Operational Phase Thermal Analysis and Design: A Comparative Study

This paper is about the modeling and design of the passive thermal control system for the European Student Earth Orbiter (ESEO) satellite. A detailed thermal model was created in Thermal Desktop software. The model was running for the operative phase which includes cycles of 28 orbits. During these 28 orbits, there are several modes (10 modes). Each mode has a specific duration, attitude (Sun-nadir), and certain internal heat dissipation. The design of the passive thermal control system was based on controlling the conductive and radiative heat exchange between the internal components and the mounting panels, between panels themselves, and controlling external radiation exchange to achieve the desired components temperature ranges. The temperature results from simulations were presented to show the expected component temperatures and to demonstrate that the passive thermal control system met the requirements of the temperature limits. The final passive thermal control design shows that the satellite components temperatures were always maintained within their required limits during the operational phase

Thermal parameters identification in the correlation of spacecraft thermal models against thermal test results

Temperatures predicted by the Thermal Mathematical Models (TMMs) used in the thermal control design of spacecraft, usually present differences with the values measured during the thermal test campaign. Therefore, the TMMs must be correlated with the thermal tests to reduce these differences to admissible values.This task can be addressed in an automatized way considering the correlation as an optimization problem, where the differences between predicted and measured temperatures are minimized. This is achieved modifying the values assigned to some parameters used in the TMMs. The main drawback of this approximation is the risk of loosing the physical sense of some model parameters. The reason is that the thermal inverse problem, that is, calculate the thermal parameters that produce a specific temperature distribution, often has not a unique solution.A methodology of automatized correlation to calculate the correct values of the model parameters, in the sense that they maintain its physical interpretation, is presented in this article. The key point relies in setting up an overdetermined system of equations. The expression to calculate the minimum number of load cases required, is developed, and several case studies are presented to validate the proposed methodology. A gradient based public available set of subroutines (TOLMIN) has been used as optimization algorithm.

High power density thermal control design of onboard phased array antenna

Thermal control of high power density phased array antenna [1] has become a critical problem for onboard seeker which is confined by compact structure and harsh flight condition [2-4], different from land-based or airborne seekers. As a key technology, thermal control of onboard phased array antenna faces the challenge of high density power element as well as worse operating temperature. Using finite volume method as theoretic foundation of numerical simulation, this paper firstly calculates temperature field and fluid field via discrete control equation group, which is transformed from continuous integration equation group according to energy reservation equation. Next,2 kinds of phased array antenna with phase change energy storage and water cooling are designed and evaluated by thermal control performance simulation. Then advice is given for reasonable assembly after temperature distribution of phased array antenna is quantified under different assembly state with the influence of contact thermal resistance. At the end, precision of temperature simulation is verified with temperature test result of phased array antenna.

Thermal Noise Decoupling of Micro-Newton Thrust Measured in a Torsion Balance

The space gravitational wave detection and drag free control requires the micro-thruster to have ultra-low thrust noise within 0.1 mHz–0.1 Hz, which brings a great challenge to calibration on the ground because it is impossible to shield any spurious couplings due to the asymmetry of torsion balance. Most thrusters dissipate heat during the test, making the rotation axis tilt and components undergo thermal drift, which is hysteretic and asymmetric for micro-Newton thrust measurement. With reference to LISA’s research and coming up with ideas inspired from proportional-integral-derivative (PID) control and multi-timescale (MTS), this paper proposes to expand the state space of temperature to be applied on the thrust prediction based on fine tree regression (FTR) and to subtract the thermal noise filtered by transfer function fitted with z-domain vector fitting (ZDVF). The results show that thrust variation of diurnal asymmetry in temperature is decoupled from 24 μN/Hz1/2 to 4.9 μN/Hz1/2 at 0.11 mHz. Additionally, 1 μN square wave modulation of electrostatic force is extracted from the ambiguous thermal drift background of positive temperature coefficient (PTC) heater. The PID-FTR validation is performed with experimental data in thermal noise decoupling, which can guide the design of thermal control and be extended to other physical quantities for noise decoupling.

Key technologies analysis and design of ultra-clean &amp; ultra-stable spacecraft for gravitational wave detection

The observation of gravitational wave enables human to explore the origin, formation and evolution of universe governed by the gravitational interaction and the nature of gravity beyond general theory of relativity. The groundbreaking discovery of Gravitational Wave by Laser Interferometer Gravitational-Wave Observatory provides a brand-new observation way. While detecting gravitational wave on ground is limited by noises and test scale, space detection is an optimized alternative to learn rich sources in range of 0.1 mHz–1 Hz. Considering the great significance of space gravitational wave detection, ESA proposed LISA project, CAS also proposed Taiji project. Due to the extremely weak gravitational wave signal and high measurement accuracy requirement, the spaceborne GW observation antenna is accomplished by three spacecrafts constitute isosceles triangle formation intersatellite interferometer. The arm length of the interferometer reaches millions of kilometers between them, and the measurement accuracy reaches pico-meter magnitude. There are many key technologies including pm magnitude space laser interferometer metrology, drag-free control using TM of Gravity Reference Sensor, [Formula: see text]N micro thruster, ultra-clean &amp; ultra-stable spacecraft, etc. This paper focuses on key technologies of the ultra-clean &amp; ultra-stable spacecraft, analyzing the design of mechanical, thermal control and magnetic clean. Moreover, it reports the preliminary results of the technological breakthrough.

Research on adaptive thermal control system of space optical remote sensor

The traditional thermal control system of the space optical remote sensor is mainly based on passive thermal control and supplemented by active thermal control of electric heater. But with the development of the remote sensor in the direction of multi-task and multi-function, the thermal control system needs to meet the requirements of low thermal control resource consumption under the condition of multi heat source and large heat load, and high adaptability under the condition of multi attitude complex orbit. The traditional thermal control system can not satisfy these new requirements. In this paper, a new adaptive thermal control system is studied. A geostationary orbit camera as an example is taken to compare the design scheme of the traditional thermal control system and the new thermal control system. The simulation results show that the new thermal control has the advantages of more optimized system resources and stronger temperature adaptability under complex tasks, which provides a new idea for the subsequent thermal control design of complex large space optical remote sensor.

Thermal design and simulation of space-borne membrane antenna

Thermal deformation of space-borne radar antenna caused by dramatic changes in orbit thermal environment has a serious effect on image qualities. In this paper, the NX TMG module was used to simulate the orbit thermal environment of the antenna, and a thermal control design was proposed. The thermal control structure consists of three layers; the top is a radiator with high emissivity surface, the middle is a multi-layer insulation, and the bottom is a highly reflective layer. The simulation results show that the thermal design could reduce the temperature gradient from 238.1 to 31.4 °C effectively.

Far-field radiative thermal rectification with bulk materials

In this paper, we explore the far-field radiative thermal rectification potential of common materials such as metals,ceramics and doped semi-conductors using radiative and thermo-radiative properties extracted from literature. Seventeen different materials are considered. The rectification coefficient is then calculated for 136 pairs of materials; each pair can be used for the two terminals of a radiative thermal diode. A thermal bias of 200 K is considered. The choice of materials and thermal bias value are only bound by data availability in literature. Obtained results, highlight new candidate materials for far-field radiative thermal rectification. They also highlight materials where thermal rectification is not negligible and should be considered with care in heat transfer calculations when considering systems subject to a comparable thermal bias and where these materials are used. Among the materials studied, undoped Indium Arsenide (InAs) shows great promise to be employed for thermal rectification, with a thermal rectification ratio reaching 96.35% in combination with other materials. Obtained results pave the way for an optimized design of thermal radiation control and management devices such as thermal diodes.

Thermal design of space solar telescope

Aiming at the thermal characteristics of space solar telescope with long working time and harsh working environment, the thermal design of space solar telescope frame and guiding telescope under extreme working conditions was carried out. Through the finite element simulation analysis and thermal equilibrium test under high and low temperature conditions, the thermal analysis and thermal equilibrium test results of the frame and the guiding telescope were compared. The temperature was controlled at 22 °C, and the temperature fluctuation of each component under the same condition was less than 1 °C, which verified the correctness of the thermal control design. At the same time, the power difference between the finite element simulation of the frame and the guiding telescope and the thermal equilibrium test was 1.2 W at high temperature and 0.8 W at low temperature. The simulation analysis is consistent with the thermal equilibrium test, and the analysis is correct and effective, which ensures the normal operation of the telescope under complex working conditions. It provides a theoretical basis for improving the reliability and thermal design optimization of the space solar telescope module and solar tracking optical system.