Browsing by Author "Van Vliet, Adry"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Accumulator testing in multiple on-ground orientations for a small Mechanically Pumped Two-phase Loop (MPTL) for CCD thermal control(50th International Conference on Environmental Systems, 7/12/2021) van Es, Johannes; Pauw, Aswin; Van Vliet, Adry; Meng, Qingliang; Zhen Ming, Zhao; van Gerner, Henk JanNLR designed and developed on request and in co-operation with BISME an Engineering Model of a Mechanically Pumped Two-phase Fluid Loop (MPTL) Thermal Control System for CCD thermal control. The objective is to provide accurate thermal control (�1 �C) and a temperature uniformity of <2 �C for nine CCD cameras. The accumulator is a crucial component of such a two-phase pumped thermal control system which allows for loop density changes, and controls the pressure and thereby temperature of the thermal control system. As the accumulator is a large volume with both vapour and liquid, the accumulator is specially designed with internal wick structures for operation in micro-gravity to assure liquid is located at the accumulator inlet and below the accumulator heaters. The design is made such that operation in multiple on-ground orientations is possible. This is demonstrated by tests. The paper starts with a brief overview of the MPTL project and the MPTL design. Subsequently the MPTL accumulator design and the test set-up are explained and test results in various orientations are presented. The paper concludes with an outlook on future MPTL developments and applications.Item Mini Mechanically Pumped Loop Modelling, Design and Tests for standardized cubesat thermal control(50th International Conference on Environmental Systems, 7/12/2021) van Es, Johannes; Ganzeboom, Thomas; van den Berg, T. H.; Van Vliet, Adry; Brouwer, Hugo S. B.; Elvik, SanderWith the miniaturization of space-borne sensors, more powerful payloads are anticipated to be used in small satellites. Therefore, new thermal concepts are required to cope with the increasing thermal dissipation and the negative effects. This paper presents a new thermal control concept to thermally standardize small satellites with power dissipation problems and making them thermally independent of their orbits. This new thermal design concept is a small Mechanically Pumped Loop (MPL). The heart of the system is the multi-parallel micro-pump (MPMP) as developed by the Netherlands Aerospace Centre (NLR). This pump concept provides a low mass MPL solution with high reliability. The article describes the concept of the loop and the pump in detail and explains how the design of the MPL takes into account the requirements imposed by CubeSats and their subsystems, thereby ensuring its compatibility with small satellites and a variety of missions. The Mini-MPL is modelled in Matlab to support MPL system design trade-offs. This model is described and modelling results are presented. Subsequently MPL tests results with a mini-MPL prototype are presented and compared with the model results to validate the model. The prototype tests demonstrate the mini-MPL performance and robust operation. Finally, the advantages and drawbacks of the system are elucidated by comparison with conventional thermal design options. The paper concludes with an outlook on further development and mini-MPL applications.