Browsing by Author "Kowalski, Lukasz"
Now showing items 1-20 of 28
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A self-calibrating closed loop circuit for configurable constant voltage thermal anemometers
(Institution of Electrical Engineers, 2015-09-17)
Article
Open Access -
Active control of the surface potential of nanostructured layers
(2016-01-21)
Article
Open AccessThe objective of this letter is to show the first results obtained with a control designed to keep the average surface potential of a nanostructured layerconstant. This condition is equivalent to keeping constant the ... -
Analyzing the performance of a miniature 3D wind sensor for Mars
(Multidisciplinary Digital Publishing Institute (MDPI), 2020-10-20)
Article
Open AccessThis paper analyzes the behavior of a miniature 3D wind sensor designed for Mars atmosphere. The sensor is a spherical structure of 10 mm diameter divided in four sectors. By setting all the sectors to constant temperature, ... -
Applications of hot film anemometry to space missions
(VDE Conference Publications, 2008)
Conference report
Restricted access - publisher's policyIn this paper the most important constraints of the wind sensors for the Martian atmosphere are described, along with an overview of the past successful designs. Practically all the data available today about the Martian ... -
Contribution to advanced hot wire wind sensing
(Centre de Publicacions del Campus Nord SCCL (CPET), 2009)
Conference lecture
Open Access -
Contribution to advanced hot wire wind sensing
(Universitat Politècnica de Catalunya, 2016-01-22)
Doctoral thesis
Open AccessThe thermal anemometry is a method which allows to estimate wind magnitude be the mean of measuring heat transfer to the ambient in a forced convection process. For Earth's atmosphere condition, this method is typically ... -
Design and smart control of sensors for optimal performance: a application to wind sensing in Mars
(2019)
Conference report
Open AccessSensor performance in terms of time response and sensitivity can be dramatically enhanced by operating sensors under what may be called a “constant state operation”. This means that any change in the sensor due to external ... -
Exploring the performance of a miniature 3D wind sensor under extreme martian winds up to the dust devil scale
(2019)
Conference report
Open AccessThe objective of this paper is to explore the performance of a miniature 3D spherical wind sensor for Mars atmosphere, working under extreme wind speeds, up to the Dust Devil scale. The experimental campaign has been made ... -
Fluid dynamics and heat transfer in the wake of a sphere
(2019-04)
Article
Open AccessDirect numerical simulation and large-eddy simulation have been performed for a heated sphere at Reynolds numbers of $Re=1000$ and $Re=10^4$, respectively. The Prandtl number for both simulations has been $Pr=0.7$. ... -
Heat flow dynamics in thermal systems described by diffusive representation
(Institute of Electrical and Electronics Engineers (IEEE), 2016-09-01)
Article
Open AccessThe objective of this paper is to analyze the dynamics of heat flow in thermal structures working under constant temperature operation. This analysis is made using the tools of sliding mode controllers. The theory is ... -
Hypobaric chamber for wind sensor testing in Martian condictions
(IEEE Press. Institute of Electrical and Electronics Engineers, 2011)
Conference report
Restricted access - publisher's policyIn this paper we will describe the installation of a low pressure stainless steel horizontal chamber to be used in preliminary tests of a Mars atmosphere wind sensor. It includes custom made additional QF ports, electric ... -
In situ size sorting in CVD synthesis of Si microspheres
(Macmillan Publishers, 2016-12-08)
Article
Open AccessSilicon microspheres produced in gas-phase by hot-wall CVD offer unique quality in terms of sphericity, surface smoothness, and size. However, the spheres produced are polydisperse in size, which typically range from 0.5¿µm ... -
Low pressure spherical thermal anemometer for space missions
(Institute of Electrical and Electronics Engineers (IEEE), 2013)
Conference report
Restricted access - publisher's policyThe novelty of this 2D thermal anemometer is the spherical compact and robust design with improved sensitivity in the range of 600-900Pa of carbon dioxide pressure and 0.25 to 10 m/s wind speed. The small size (11.2mm ... -
Model identification of time-varying diffusive systems
(2018)
Conference report
Restricted access - publisher's policyThis paper presents a characterization method based on diffusive representation for a class of linear or nonlinear time-varying diffusive systems. The system variation with time may come as a result of the own actuation ... -
Multiphysics simulation of REMS hot-film anemometer under typical martian atmosphere conditions
(COMSOL, 2010)
Conference report
Open AccessThe purpose of this paper is to describe numerical electro-thermal simulations of the REMS wind sensor unit [3] and the results obtained by using COMSOL multiphysics. This device is a hot-film anemometer for 2D wind ... -
On the boundary layer development and heat transfer from a sphere at moderate Reynolds numbers
(2018)
Conference report
Restricted access - publisher's policyDirect and large-eddy numerical simulations have been performed for a heated sphere at Reynolds numbers 200, 300, 500, 750, 1000 and 104, in the context of the development of a spherical wind sensor for Mars atmosphere ... -
On the effects of free-stream turbulence intensity in the fluid flow and heat transfer from a sphere at subcritical Reynolds numbers
(2018)
Conference lecture
Restricted access - publisher's policyIn this work, the effect of the free-stream turbu-lence on the heat transfer and the near wake behind a sphere is studied at moderate Reynolds numbers of ¿¿ ¿ ¿¿¿¿ and ¿¿ ¿ ¿¿¿. Turbulence delays the sep-aration of the ... -
Open loop testing for optimizing the closed loop operation of chemical systems
(Pergamon Press, 2020-04-06)
Article
Open AccessOne way to optimize the operation of chemical systems consists on using closed loop controls while the system is operated. This way, it is possible to optimize the operating point in the plant, process or chemical system ... -
REMS: the environmental sensor suite for the Mars Science Laboratory rover
(2012-09)
Article
Restricted access - publisher's policyThe Rover Environmental Monitoring Station (REMS) will investigate environ- mental factors directly tied to current habitability at the Martian surface during the Mars Sci- ence Laboratory (MSL) mission. Three major ... -
Self-calibrating closed-loop circuit for configurable constant voltage thermal anemometers
(Institution of Electrical Engineers, 2015-09-17)
Article
Open AccessA new circuit is described which applies a configurable voltage across an RTD while the current flowing through it is measured with a current mirror. The circuit also allows working with voltages above the IC supply voltage ...
