Altitude-Test-Chamber Investigation of the Endurance and Performance Characteristics of the J65-W-7 Engine at a Mach Number of 2.0

An investigation of the endurance characteristics, at high Mach number, of the J65-W-7 engine was made in an altitude chamber at the Lewis laboratory. The investigation was made to determine whether this engine can be operated at flight conditions of Mach 2 at 35,000-feet altitude (inlet temperature, 250 F) as a limited-service-life engine Failure of the seventh-stage aluminum compressor blades occurred in both engines tested and was attributed to insufficient strength of the blade fastenings at the elevated temperatures. For the conditions of these tests, the results showed that it is reasonable to expect 10 to 15 minutes of satisfactory engine operation before failure. The high temperatures and pressures imposed upon the compressor housing caused no permanent deformation. In general, the performance of the engines tested was only slightly affected by the high ram conditions of this investigation. There was no discernible depreciation of performance with time prior to failure

Effect of variable-position inlet guide vanes and interstage bleed on compressor performance of a high-pressure-ratio turbojet engine

Increased guide-vane turning resulted in poorer overall performance, the decrease being greatest at the highest rotor speed. Rotating stall originating at the tips of the first stage correlated with the knee in the stall-limit line. Increasing guide-vane turning shifted the first-stage stall-free performance and the knee in the stall-limit line to a lower engine speed. Opening the interstage bleed reduced the minimum rotor speed at which stall-free performance of the first stage was possible and tended to eliminate the knee in the stall-limit line

Comparison of turbojet-engine altitude performance characteristics and ignition limits with MIL-F-5624A fuel, grades JP-3 and JP-4

The performance of MIL-F-5624A fuels, grades JP-3 and JP-4, was investigated in an axial-flow turbojet engine over a range of altitude conditions of 10,000 to 55,000 feet. Examination of the fuel flow, combustion efficiency, and net thrust specific fuel consumption showed the grade JP-4 fuel to be slightly inferior to the grade JP-3 fuel, although the altitude ignition limits were essentially equal for the two fuels over a range of flight Mach numbers and fuel-inlet temperatures

NACA Research Memorandums

Memorandum presenting an investigation of a full-scale afterburner with high burner-inlet velocity conducted to determine burner performance with several variations in burner design. Variables receiving particular attention were flameholder design and burner length. Results regarding diffuser performance, performance of the reference two-V-gutter flameholder, designs to improve combustion for high-velocity conditions, and operational characteristics are provided

Cohort feasibility study of an intermittent pneumatic compression device within a below-knee cast for the prevention of venous thromboembolism

OBJECTIVES: To determine the likely enrolment rate of eligible participants into a randomised controlled trial (RCT) in which a within-cast intermittent pneumatic compression device using Jet Impulse Technology (IPC/JIT) is 1 of 3 possible interventions in a RCT for the prevention of venous thromboembolism (VTE) in the clinical setting of isolated lower limb cast immobilisation. DESIGN: A prospective, open-label feasibility study of the IPC/JIT device placed within a lower limb cast. SETTING: Wellington Regional Hospital Fracture Clinic.PARTICIPANTS: Individuals aged 18-70 who presented with a lower limb injury requiring a minimum of 4 weeks below-knee cast immobilisation. INTERVENTION: Placement of an IPC/JIT device within lower limb cast. OUTCOME MEASURES: The main outcome measure was the proportion of eligible participants who participated in the feasibility study. Secondary outcome measures included adherence to device usage throughout the study, ease of application of the device and adverse events potentially associated with its use. RESULTS: The proportion of potentially eligible participants for the IPC/JIT device was only 7/142 (5%), 95% CI 2 to 9.9. Devices were used for a mean (range) of 4.1 (1.9 to 10.2) hours per day and none of 7 participants had adequate adherence to the device. 3 of the 7 participants suffered an adverse event, including 1 deep vein thrombosis, 2 dorsal foot ulcer and 1 skin maceration. CONCLUSIONS: A within-cast IPC/JIT device is unlikely to be a feasible randomisation arm for a RCT assessing possible interventions for the reduction of VTE risk in the clinical setting of lower limb injury requiring below knee cast immobilisation for a minimum of 4 weeks