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

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1357
Author(s):  
Linxiao Cong ◽  
Jianchao Mu ◽  
Qian Liu ◽  
Hao Wang ◽  
Linlin Wang ◽  
...  
Keyword(s):  
Thermal Noise ◽  
Rotation Axis ◽  
Electrostatic Force ◽  
Thermal Control ◽  
Positive Temperature Coefficient ◽  
Torsion Balance ◽  
Positive Temperature ◽  
Thermal Drift ◽  
Low Thrust ◽  
Z Domain

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.

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

2021 ◽  
Author(s):  
Lin-xiao Cong ◽  
Jian-chao Mu ◽  
Qian Liu ◽  
Hao Wang ◽  
Lin-lin Wang ◽  
...  
Keyword(s):  
Pid Control ◽  
Thermal Noise ◽  
Thermal Control ◽  
Torsion Balance ◽  
Low Thrust ◽  
Vector Fitting ◽  
Wave Detection ◽  
Heating And Cooling ◽  
Z Domain ◽  
Physical Quantities

The space gravitational wave detection and drag free control requires the micro-thruster to have very low thrust noise within 0.1mHz~100mHz, which poses a great challenge to the ground thrust test. The evaluation and decoupling of thermal noise are the difficulties in the application of torsion balance for most thrusters dissipate heat in the experiment. The research has adopted a calibration scheme of micro-Newton thrust torsion balance. On the basis of Lisa Pathfinder's former research and using ideas inspired from PID control and multi time scale (MTS) for reference, the paper proposes to expand the state space of temperature to be applied on thrust prediction based on fine tree regression (FTR), to subtract the thermal noise filtered by transfer function fitted with z-domain vector fitting (ZDVF). The results show that the thrust amplitude thrust density in diurnal temperature fluctuation is decoupled from 24μN/Hz1/2 to 4.9μN/Hz1/2 at 0.11mHz. And the 1μN square wave modulations of electrostatic fins (ESF) is extracted from the simultaneously ambiguous background of temperature for PTC's heating and cooling. The FTR method is well demonstrated in thermal noise decoupling and can guide the design of thermal control and be extended to other physical quantities for noise decoupling.

scholarly journals Development of Auto Thermal Control Device For Space Air - Conditioning

2021 ◽  
pp. 193-204
Author(s):  
Akinde Olusola Kunle ◽  
Maduako Kingsley Obinna ◽  
Akande, Kunle Akinyinka ◽  
Adeaga Oyetunde Adeoye
Keyword(s):  
Temperature Coefficient ◽  
Room Temperature ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Thermal Control ◽  
Positive Temperature Coefficient ◽  
Control Device ◽  
Thermal Source ◽  
Positive Temperature ◽  
Ntc Thermistor

Auto Thermal Control device is an electronic based device which employs the application of temperature sensors to controlling household appliances without human interference directly. In this work, thermal source is used to regulate electrical fan and room heater depending on ambient temperature. The room heater, which is adjusted to a set temperature, switches ‘ON’ when the temperature of a room is low (cold). While the same is switches ‘OFF’ with increase in the room temperature. This triggers ‘ON’ an electric fan at different speeds, and thus cools the room. A temperature sensor, tthermistor, monitors change in room temperature. Two types of thermistor exists: Positive Temperature Coefficient, PTC. An increasee in the resistance of PTC results in increasee in temperature). In the Negative Temperature Coefficient, NTC; a decreasee in resistance yields to temperature increase. This article explored a NTC thermistor. The design could be a ready product in the market of the developing nation where environmental automation is yet fully deployed.

scholarly journals Enhanced positive temperature coefficient behavior of the high-density polyethylene composites with multi-dimensional carbon fillers and their use for temperature-sensing resistors

RSC Advances ◽  
2017 ◽  
Vol 7 (19) ◽  
pp. 11338-11344 ◽  
Author(s):  
Jun-Wei Zha ◽  
Dong-Hong Wu ◽  
Yu Yang ◽  
Yun-Hui Wu ◽  
Robert K. Y. Li ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Temperature Coefficient ◽  
Service Time ◽  
High Density Polyethylene ◽  
Thermal Control ◽  
Positive Temperature Coefficient ◽  
High Density ◽  
Temperature Sensing ◽  
Positive Temperature ◽  
Carbon Fillers

The synergistic effect of the modified CB and MWNT can improve the service time of positive temperature coefficient materials under harsh thermal control conditions.

KANTHAL 70

Alloy Digest ◽  
1981 ◽  
Vol 30 (9) ◽  
Keyword(s):  
Operating Temperature ◽  
Heat Treating ◽  
Positive Temperature Coefficient ◽  
Pure Nickel ◽  
Voltage Source ◽  
Voltage Regulator ◽  
Positive Temperature ◽  
Automotive Applications ◽  
Resistance Thermometers ◽  
In Series

Abstract KANTHAL 70 alloy was designed to provide a high positive temperature coefficient to electrical resistance comparable with that of pure nickel; however, it has much higher electrical resistivity than pure nickel. This makes it useful as a voltage regulator when placed in series with another electrical device across a fluctuating voltage source. Kanthal 70 has a maximum recommended operating temperature of 600 C and is used widely in resistance thermometers and in various appliance and automotive applications. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-270. Producer or source: The Kanthal Corporation.

Sign in / Sign up

Export Citation Format

Share Document