Modeling To Heat And Moisture Transfer In Pilot-anti-g Suit With Bladders-Environment System

To protect the fighter pilots from injurious G-load resulting from fighter high acceleration,bladder anti-G garments are designed specially. The bladders are impermeable, they will be flattedand compress skin surface to protect pilots from blacking-out during periods of high acceleration.Because of impermeable bladders and high thermal resistance, anti-G garments always produce heatstress on wearers even in a moderate environment. The heat stress will reduce pilot’s work efficiencyand decrease their endurance to the high G-load. To mitigate pilot heat stress in variousenvironments, research on thermal performance of anti-G garment is essential to provide criticalinformation for improving the garment design. This work focuses on a theoretical investigation ofhow heat and moisture can transfer in pilot-anti-G suit-environment system and how to optimize thematerials of the anti-G suit for decreasing index of the thermal stress.First, the background of the discussed topics and realistic significance are expounded.Meanwhile, the research situation of anti-G suit, human thermoregulatory model and heat andmoisture transfer model for clothing is concluded and summarized. Studying on heat and moisturemechanisms in pilot-anti-G suit-environment and optimizing the materials of the anti-G suit are twomain research directions. The research method is determined.To investigate the bladder over different skin surface on the heat and moisture transfer of pilot,an85-node model for the pilot is developed based on the25-node human thermoregulatory model.This human body model is interfaced with the coupled heat and moisture transfer model of clothing.The simulating results agree well with the published experimental data.On the base of the model developed, the influences of phase change materials (PCM) on indexof thermal stress for the pilot. To optimize the PCM, a numerical orthogonal analysis method is used.The best optimization scheme is provided.Then, a3D heat and moisture transfer model for the clothed human body is developed based onthe3-D scanning data of the human body. The Finite Element Method (FEM) is used to solve thegoverning equations. For a multi-layer clothing sub-system, a simple solution scheme is given bydefining the air or bladder element. By using the model, the heat and moisture transfer in generalclothed human body and pilot-anti-G suit-environment system are simulated.