21, September 2018

ESA Open Invitation to Tender AO9443
Open Date: 18/09/2018
Closing Date: 05/11/2018 13:00:00

Status: ISSUED
Reference Nr.: 18.123.03
Prog. Ref.: GSTP Element 1 Dev
Budget Ref.: E/0904-611 – GSTP Element 1 Dev
Special Prov.: GB
Tender Type: C
Price Range: 200-500 KEURO
Products: Launchers / Propulsion / Liquid propulsion engines – BB / Flow control and distribution devices (Pipes, Valves, Actuators, Filters, …) / Orbital Transportation & Re-entry Systems / Propulsion and Reboost / Chemical Propulsion Systems ¿ BB / Other
Techology Domains: Propulsion / Supporting Propulsion Technologies and Tools / Propellants
Establishment: ESTEC
Directorate: Directorate of Tech, Eng. & Quality
Department: Mechanical Engineering Department
Division: Propulsion & Aerothermodynamics Division
Contract Officer: Almeida, Rudolfo
Industrial Policy Measure: N/A – Not apply
Last Update Date: 18/09/2018
Update Reason: Tender issue

The purpose of the activity is two-fold: to use an acoustic beam for sounding the fluid location in a tank. to show the abilityof induce fluid movements and control of the free surface for liquid/gas mixtures, including those of cryogenic flows.Management of fluids on fuel tanks of spacecraft and launcher upper stages under microgravity conditions has always presented a challenge, because it does not naturally accumulate in a neat shape near the exit port. Gauging requires measurement or knowledge of the shape of the fluid free surface in microgravity. Knowledge of the residual quantity and location of propellant is essential for management andcontrol of both satellites and launcher upper stages, for the latter in particular if multiple firings are anticipated. Manipulation of fluids in partially filled tanks serves the purpose to ensure it is connected to the exit port.In a previous TRP activity, ultrasonic transducers have been used to impose motion in fluids (water, kerosene and LN2), as result of asymmetric flow patterns in the close vicinity of the transducer. This offers the possibility that fluids could be managed with an array of ultrasonic transducerswhere phase and amplitude control to each unit are used to generate focused acoustic beams, which can manipulate the fluids. Base on those results, it is here proposed to implement an array of transducers, and through phased driving of these, to generate a directed acoustic beam. With help of this beam one can sound the fluid location in the tank. Using a range of experimental setups (e.g. tipping the tank to collect the fluid at one end; containing the fluid in balloons, and so on), the effects of varying gas/fluid boundary locations and shapes will be investigated to extend the demonstration done in the first study, using liquid only, to liquid/gas mixtures, showing the ability to induce fluid movement and control of the free surface also under these circumstances.A specific set of trials will include an assessment of the viability of mounting the transducer array outside the tank and sounding through the wall using a typical tank wall construction (including Ti and CFRP). Some of the transducers will be immersed in fluid attached to the container walls by surface tension, and some will be in the gas-filled part of the vessel. Further, the test equipment and set-up will be adapted for a future accommodation and operation on board a parabolic flight to demonstrate the technique under micro-gravity conditions. In addition, to show the compatibility of transducers in operation at cryogenic temperature and, if a safe configuration can be designed, first trials with acoustic liquid manipulation and sensing with LH2 will be performed on ground. Finally, the experimental results will be used also to validate numerical tools for simulation of the coupling between acoustics and fluid behavior.

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