Browsing by Author "Castro, Charlton"
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Item Development and Testing of a Two-Phase Mechanically Pumped Loop for Active Antennae(2023 International Conference on Environmental Systems, 2023-07-16) van Gerner, Henk Jan; Kunst, Romaine; van den Berg, T.H; van Es, Johannes; Tailliez, Anne; Walker, Andy; Ortega, Cristina; Iriarte, Mónica; Roldan, Nuria; Ortega Castañeda, Christian; Castro, CharltonThe satellite telecommunications industry is currently undergoing significant evolutions. Future communication satellites need to accommodate a rapidly growing demand in data transfer, combined with more flexibility. For example, there is a strong need for Very High Throughput Satellites capable of delivering up to Tb/s over wide coverage areas. This is only possible when an active phased array antenna is used. However, cooling of active antennas requires the use of a highly efficient thermal control system because it has many heat sources (from hundreds to several thousands), high local heat fluxes (20 W/cm² at evaporator interface), high overall dissipation (around 10 kW), and isothermal requirements on the amplifier chain. These conditions are very difficult to meet with current thermal control solutions (e.g. heat pipes or loop heat pipes), but require a two-phase mechanically pumped fluid loop (MPL). In a MPL, a pump circulates a fluid which evaporates when it absorbs the waste heat from the active antenna. In the IMPACTA project, a demonstrator for such a MPL is being designed and build. This paper describes the test results for the IMPACTA demonstrator. The demonstrator is able to cool a total heat load of 9.8 kW divided over 10 parallel branches with a better than 2°C spatial temperature uniformity over the heat sources. In an active antenna application, the heat load can be unevenly distributed over the different branches. Tests show that even in the extreme case when half of the branches are turned off and the other half are set to full power, no sign of dry-out or too high temperatures is observed, demonstrating the ability of the MPL to cool imbalanced payloads. The demonstrator was tested in 3 different orientations and the test results are similar for all orientations, indicating that the system is not sensitive to gravity effects.Item Development of an Innovative Diaphragm Pump and Two-Phase Mechanically Pumped Loop for Active Antennas(51st International Conference on Environmental Systems, 7/10/2022) Castro, Charlton; Ortega, Christian; Picton, Kevin; Iriarte, Monica; Ortega, Cristina; van Gerner, Henk Jan; van den Berg, Ramon; van Es, JohannesThe development of Active Phased Array Antennas (APAAs) is a key enabler to effectively accommodate the growing demand of data transfer in commercial telecommunication satellites. A highly efficient and integrated thermal management system is required so as to reject the waste heat produced by the antenna�s Solid State Power Amplifiers (SSPAs). The development of such a thermal control system presents a number of technical challenges, chief among them being the large number of heat sources involved (typically ranging from 100 to 1000, with varying duty cycles), the need for spatial and temporal isothermal conditions across the set of SSPAs, as well as a low thermal gradient between the SSPAs and the working fluid, high total heat dissipation (10+ kW), high heat flux (20+ W/cm^2 at the evaporator�s interface) and large distances between the radiator and the payload, among others. An international consortium led by AVS is currently developing an ammonia two-phase pumped loop for APAAs within the frame of the IMPACTA project. MPLs (two-phase pumped loops in particular) are remarkably well suited for applications involving large heat loads, transfer of thermal energy over large distances (e.g. distributed payloads), high heat fluxes and payloads with tight temperature stability requirements. In addition, a novel positive displacement pump for spacecraft thermal control is being developed by AVS. The pump features a diaphragm architecture, piezoelectric actuator and passive check valves. A series of performance characterization tests of the EM have been conducted using a two-phase mechanically pumped loop test system in laboratory conditions. It is the purpose of the present paper to provide an overview of the IMPACTA project, current status and goals, as well as a description of the PDPump project, outlining the design and main requirements, as well as the development history and current status.Item Preliminary design of a mechanically pumped cooling system for active antennae(50th International Conference on Environmental Systems, 7/12/2021) Jan van Gerner, Henk; van den Berg, Ramon; van Es, Johannes; Tailliez, Anne; Walker, Andy; Ortega, Cristina; Iriarte, M�nica; Castro, CharltonThe satellite telecommunications industry is currently undergoing significant evolutions. Future communication satellites need to accommodate a rapidly growing demand in data transfer, combined with more flexibility. For example, there is a strong need for Very High Throughput Satellites capable of delivering up to Tb/s over wide coverage areas and an active phased array antenna is a powerful enabler to achieve that. However, cooling of active antennas requires the use of a highly efficient thermal control system because it has many heat sources (hundred or more), high local heat fluxes (20W/cm� at evaporator interface), high overall dissipation (around 10 kW), and isothermal requirements on the amplifier chain. These conditions are very difficult to solve with current thermal control solutions (e.g. heat pipes or loop heat pipes), but require a two-phase mechanically pumped fluid loop (MPL). In a MPL, a pump circulates a fluid which evaporates when it absorbs the waste heat from the active antenna. In the EU funded IMPACTA project, a demonstrator for such a MPL is being designed and built. This paper describes the preliminary design for this demonstrator, including the fluid selection and tests on evaporator samples.