Atmospheric Cloud Physics Laboratory Thermal Control

1979 ◽  
Vol 101 (2) ◽  
pp. 191-196 ◽  
Author(s):  
J. L. Moses ◽  
G. L. Fogal ◽  
T. R. Scollon
Keyword(s):  
Thermal Control ◽  
Cloud Microphysics ◽  
Test Results ◽  
Cloud Physics ◽  
Expansion Chamber ◽  
Physics Laboratory ◽  
Thermal Requirements ◽  
Control Concept ◽  
Control Capability ◽  
Flight Hardware

This paper presents the development background and the present status of the Atmospheric Cloud Physics Laboratory (ACPL) thermal control capability. The ACPL, a Spacelab Payload, is currently in the initial flight hardware development phase for a first flight scheduled in June 1981. The ACPL is intended as a facility for conducting a wide variety of cloud microphysics experimentation under zero gravity conditions. The cloud chambers, which are key elements of the ACPL, have stringent thermal requirements. Thus the Expansion Chamber inner walls must be uniform to within ±0.1°C during both steady state and transient operation over a temperature range of +30 to −25°C. Design progression of the Expansion Chamber, from early inhouse NASA-MSFC concepts (including test results of a prototype chamber) to the thermal control concept currently under development at General Electric, is discussed.

Numerical simulation of fairing separation test for hypersonic air breathing vehicle

2016 ◽  
Vol 231 (2) ◽  
pp. 319-325 ◽  
Author(s):  
Ankit Raj ◽  
K Anandhanarayanan ◽  
R Krishnamurthy ◽  
Debasis Chakraborty
Keyword(s):  
Structural Integrity ◽  
Test Results ◽  
Air Breathing ◽  
Aerodynamic Loads ◽  
Pressure Distributions ◽  
Ground Test ◽  
Computational Fluid Dynamics Simulations ◽  
Euler Solver ◽  
Dynamics Simulations ◽  
Flight Hardware

Fairings are provided to cover hypersonic air breathing vehicle to protect it from adverse aerodynamic loading and kinetic heating. Separation dynamics of fairings is an important event in the launch of vehicle. Extensive computational fluid dynamics simulations are carried out for the design of fairings and vehicle and selection of time sequences of various separation events. A ground test of fairing separation is conducted in the sled facility to check the structural integrity and functionality of various separation mechanisms and flight hardware. Simulations have been carried out to study the separation dynamics of fairings at test conditions using grid-free Euler solver to get the aerodynamic loads and the loads are integrated to get the trajectory of fairings. The aerodynamic loads are provided to verify the structural integrity of various components and the trajectory of panels is used in the test planning. The pressure distributions on the vehicle are compared with the test results.

Measurement and Prediction of Temperature Distributions in Optical Elements in the Millikelvin Regime

2000 ◽  
Author(s):  
Jay Ambrose ◽  
Ab Hashemi ◽  
Julie Schneider ◽  
Dave Stubbs ◽  
Kim Aaron ◽  
...  
Keyword(s):  
Test Results ◽  
Optical Elements ◽  
Small Perturbations ◽  
Thermal Requirements ◽  
Steady State Temperature ◽  
Uncertainty Estimates ◽  
Model Correlation ◽  
Thermal Perturbations ◽  
Good Agreement ◽  
Test Correlation

Abstract This paper describes analytical and experimental thermal results for a 33.5 cm diameter plano mirror under conditions of small thermal perturbations (steady-state temperature gradients of 10–100 mK). These tests are intended to support verification of specific thermal requirements for a space interferometer. The primary thermal requirement is knowledge/control of temporal changes in mirror gradients to the 1 mK (0.001 K) level. Tests were performed with small heat inputs to the back of the mirror, which was suspended in a thermally-uniform shroud. Correlation of thermal models for both conductively and radiatively-heated test configurations were performed, and results indicate very good agreement between the thermal model predictions and the temperature measurements. The modeling uncertainty based on the test correlation is estimated to be ±3 mK for absolute temporal comparisons. Comparisons for temporal change of gradient are shown to be within 1 mK for small perturbations. The paper describes the test setup, test results, model correlation and uncertainty estimates.

Flood Control Mechanism of Multiple Dams Constructed in a Series Based on Cascade Method

2015 ◽  
Vol 10 (3) ◽  
pp. 475-485
Author(s):  
Hideo Oshikawa ◽  
◽  
Toshimitsu Komatsu ◽  
Keyword(s):  
Conventional Method ◽  
Flood Control ◽  
Control Mechanism ◽  
Water Discharge ◽  
High Water ◽  
Control Approach ◽  
Flood Peak ◽  
Control Concept ◽  
Control Capability ◽  
Cascade Method

Using numerical simulation, we clarified the mechanism that the flood control capability is dramatically strengthened by using multiple serial dams efficiently, based on a new flood control concept that let dams overflow through emergency spillways. Numerical analysis results for a group of dry dams were used to quantitatively evaluate this effect and to derive an empirical formula. The conventional flood control approach sets the design high water discharge of individual dams, even when dams are constructed serially, ensuring that no overflows occurs in any of the dams, here called the “conventional” method. By comparing the group of dry dams based on the conventional method and a method on the same scale but set based on a new concept that we called Cascade method, we found that when the flood peak is cut in conventional control, the latter half of the cutoff flood peak must be cut again, making flood control redundant. The Cascade method avoids this redundancy in storage use and cuts the flood peak efficiently and linearly.

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