Decoupled Method for Reconstruction of Surface Conditions From Internal Temperatures On Ablative Materials With Uncertain Recession Model
Obtaining measurements of flight environments on ablative heat shields is both critical for spacecraft development and extremely challenging due to the harsh heating environment and surface recession. Thermocouples installed several millimeters below the surface are commonly used to measure the heat shield temperature response, but an ill-posed inverse heat conduction problem must be solved to reconstruct the surface heating environment from these measurements. Ablation can contribute substantially to the measurement response making solutions to the inverse problem strongly dependent on the recession model, which is often poorly characterized. To enable efficient surface reconstruction for recession model sensitivity analysis, a method for decoupling the surface recession evaluation from the inverse heat conduction problem is presented. The decoupled method is shown to provide reconstructions of equivalent accuracy to the traditional coupled method but with substantially reduced computational effort. These methods are applied to reconstruct the environments on the Mars Science Laboratory heat shield using diffusion limit and kinetically limited recession models.
Mars Science Laboratory (MSL) Entry, Descent, and Landing Instrumentation (MEDLI): Complete Flight Data Set
......................................................................................................................................... 1 1.0 Introduction ................................................................................................................. 2 2.0 Hardware Description ................................................................................................ 3 2.1 MEADS Overview ........................................................................................................ 3 2.2 MISP ............................................................................................................................. 5 2.3 SSE ................................................................................................................................ 7 3.0 MEADS PERFORMANCE...................................................................................... 12 3.1 Calibration and System Error Modeling ..................................................................... 12 3.1.1 Calibration Approach .................................................................................................. 12 3.1.2 System Error Modeling ............................................................................................... 13 3.2 Hardware Performance ............................................................................................... 14 3.2.1 MEADS Pressure Sensor Circuit Verification ............................................................ 14 3.2.2 MEADS Thermocouple Circuit Verification .............................................................. 15 3.2.3 MEADS Measurement Data ....................................................................................... 15 3.3 Flight Data Reconstruction ......................................................................................... 16 3.3.1 Reconstruction Methodology ...................................................................................... 16 3.3.2 Trajectory Reconstruction Results .............................................................................. 18 4.0 MEDLI Integrated Sensor Plug (MISP) Performance .......................................... 19 4.1 MISP Hardware Uncertainties .................................................................................... 19 4.2 MISP Thermocouples ................................................................................................. 19 4.2.1 Accuracy in Thermocouple EMF Output ................................................................... 19 4.2.2 Accuracy of Indicated In Situ Temperature ................................................................ 21 4.3 HEAT Sensor .............................................................................................................. 23 4.3.1 Isotherm Temperature: 721  60C ............................................................................ 23 4.3.2 Isotherm Depth............................................................................................................ 24 4.4 Summary of Hardware Uncertainties.......................................................................... 27 4.4.1 MISP Thermocouple Temperature Overall Uncertainty............................................. 27 4.4.2 HEAT Sensor Overall Uncertainty ............................................................................. 27 4.4.3 Arc Jet Testing and Verification ................................................................................. 28 4.5 Hardware Performance ............................................................................................... 28 4.5.1 MISP Thermocouple Circuit Verification .................................................................. 28 4.5.2 MISP HEAT Circuit Verification ............................................................................... 29 4.6 Flight Data .................................................................................................................. 29 4.6.1 Thermocouples ............................................................................................................ 29 4.6.2 HEAT .......................................................................................................................... 30 4.7 Model Validation and Reconstruction ........................................................................ 31 5.0 Conclusions ................................................................................................................ 33 6.0 References .................................................................................................................. 34 7.0 Appendices ................................................................................................................. 38 .................................................................................................................................. 38 Appendix A .................................................................................................................................. 74 Appendix B
A STUDY ON ORGANIZED RETAILING AND ITS CHALLENGES AND RETAIL CUSTOMER SERVICES
India is becoming most favored retail destination in the world. Today retail sector contributing 10% to countryâ€™s GDP. Indian retail industry is ranked among the ten largest retail markets in the world. The change of attitudes of Indian consumers and the emergence of organized retail formats have transformed the face of retailing in India. Organized retailing offers huge potential for future growth of retailing in India. This paper provides information about the growth of retailing in India. And also focuses on the challenges faced by organized retail sector in India. It also emphasize on major players of retailers in India and customer services provided by the retailers. This paper also deals with various retail formats and the opportunities for the growth of retail industry in India and also provides some suggestions to overcome the challenges.