摘要

Venting is an important aspect in the structural design of Launch vehicles. It plays an important role in relieving the entrapped air inside the compartments to outside.
Vent scheme design for an unmanned reentry body configuration like crew module capsule, venting methodology used in the design & analysis of the same is brought out in this paper. Vent schemes are provided in order to estimate the differential pressure across the compartments.
This work comprises of estimating the compartment and differential pressure values which are used in the structural assessment of the crew module compartment. The novelty of this work is to provide relief in the overall assessment of load on the structure.
Design of the vent type and positioning of vent ports based on CFD studies and mass flow rate across the vents has been discussed in this paper. Various parameters influencing the venting process and inputs considered in the theoretical analysis are presented here.
In-house software MPVENT has been developed and is used in theoretical calculations. Based on the computations carried out by the software, proper vent scheme was designed and the same vent scheme was implemented in the crew module which was part of the CARE mission by ISRO. The unmanned crew module capsule was a payload in the ISRO's heaviest launch vehicle GSLVMKIII's maiden flight.
The crew module compartment successfully completed the mission's objective and the vent system designed for the same was proved in the flight. Pressure sensors mounted in the compartment measured the pressure values inside the body. Computed compartment pressure and differential pressure results are compared against flight results in this paper.