Engineering topics

Alvarez, Erika

Publications and source records attributed to Alvarez, Erika.

2 records

NASA NTRS2011

Small Scale Turbopump Manufacturing Technology and Material Processes

As part of an internal research and development project, NASA Marshall Space Flight Center (MSFC) has been developing a high specific impulse 9,000-lbf LOX/LH2 pump-fed engine testbed with the capability to throttle 10:1. A Fuel Turbopump (FTP) with the ability to operate across a speed range of 30,000-rpm to 100,000-rpm was developed and analyzed. This small size and flight-like Fuel Turbopump has completed the design and analysis phase and is currently in the manufacturing phase. This paper highlights the manufacturing and processes efforts to fabricate an approximately 20-lb turbopump with small flow passages, intricately bladed components and approximately 3-in diameter impellers. As a result of the small scale and tight tolerances of the hardware on this turbopump, several unique manufacturing and material challenges were encountered. Some of the technologies highlighted in this paper include the use of powder metallurgy technology to manufacture small impellers, electron beam welding of a turbine blisk shroud, and casting challenges. The use of risk reduction efforts such as non-destructive testing (NDT) and evaluation (NDE), fractography, material testing, and component spin testing are also discussed in this paper.

Alvarez, Erika↗

NASA NTRS2010

Lunar Surface Access Module Descent Engine Turbopump Technology: Detailed Design

The need for a high specific impulse LOX/LH2 pump-fed lunar lander engine has been established by NASA for the new lunar exploration architecture. Studies indicate that a 4-engine cluster in the thrust range of 9,000-lbf each is a candidate configuration for the main propulsion of the manned lunar lander vehicle. The lander descent engine will be required to perform multiple burns including the powered descent onto the lunar surface. In order to achieve the wide range of thrust required, the engines must be capable of throttling approximately 10:1. Working under internal research and development funding, NASA Marshall Space Flight Center (MSFC) has been conducting the development of a 9,000-lbf LOX/LH2 lunar lander descent engine technology testbed. This paper highlights the detailed design and analysis efforts to develop the lander engine Fuel Turbopump (FTP) whose operating speeds range from 30,000-rpm to 100,000-rpm. The capability of the FTP to operate across this wide range of speeds imposes several structural and dynamic challenges, and the small size of the FTP creates scaling and manufacturing challenges that are also addressed in this paper.

Alvarez, Erika↗