Re-Entry Simulation

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Re-Entry Simulation Chamber

The aim of the test facility is the simulation the mechanical, thermal and atmospheric loads on critical parts during the re-entry phase of reusable launchers or spacecraft for planetary exploration. The main part of the device is a completely water cooled stainless steel vacuum chamber operating at a pressure of better than 10-6 mbar or with increasing gas pressures of N2, H2, O2 up to atmospheric pressure. The control of the gas environment is performed by means of a Pfeiffer valve EVR 116 together with a Pfeiffer RVC 300 control unit.

A high-performance self-adjusting inductive heating system with an output power of 30 kW (Plustherm TN 30) is implemented to achieve temperatures up to 2500 °C with a heating rate of more than 50 K/s (depending on material). Various induction coils are available for a multitude of sample shapes and dimensions to ensure optimum inductive coupling of the heating power. Customer-specific solutions are being manufactured in house. Temperature measurements are performed with thermocouples. with a quotient pyrometer Impac ISQ 10 LO (range 300° to 2500 °C), or a combination thereof. Special Infrasil windows in the observation ports guarantee an accurate pyrometrical determination of the sample surface.

re_entry_1Applications are thermal shock testing, thermal cycling and gas cycling tests, thermo-mechanical tests and combinations thereof, e.g. sintering or hot-pressing.

Applications are thermal shock testing, thermal cycling and gas cycling tests, thermo-mechanical tests and combinations thereof, e.g. sintering or hot-pressing.

The vacuum chamber is placed in a servo-hydraulic test machine LF 70S from walter & bai. Dynamic loads of up to 70 kN with a frequency of up to 70 Hz and a variety of signal shape can be applied on the test samples. Both hot and cold gripping systems are available. Strain measurements are performed either by strain gauge or by a non-contacting system.

All functions of the device are completely microcomputer-controlled, and the highly sophisticated control software allows a convenient and reliable acquisition of all relevant process parameters.

Technical Data Summary
  • Diameter 600 mm, usable sample height 500 mm (without extension flanges)
  • Heating power 30 kW, frequency 20<>150 kHz self-optimising
  • Customer specific induction coils for critical applications on request
  • Fully computerised temperature and heating control
  • Temperature measurement by pyrometers or thermocouples
  • Vacuum better than 10 -6 mbar
  • Automatic pressure and atmosphere composition control
  • Mechanical loads up to 70 kN, static or with a frequency up to 70 Hz (sinus, rectangular, triangle, …)
  • All relevant process parameters controlled and recorded by microcomputer
Laser speckle extensometer

re_entry_2The re-entry chamber was equiped recently with a high resolution laser speckle extensometer. The extensometer comprises a PC-based video processor, which continually measures the displacement of two speckle patterns, recorded by two video cameras and two lasers. The two displacements are converted into strain signal, which is send to a control and evaluation system for data handling.

The advantages of a contact free extensometer are:

  • No specimen preparation
  • No Moving part, maintenance free
  • Two dimensionality
  • Arbitrary initial gauge lengths: 0<>250mm
  • Testing temperatures up to 1600°C
  • Measuring of E-moduli and breaking strains with a single system