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# Accession Number:

## AD0839137

# Title:

## COMPUTING THE CRITICAL VELOCITY OF A TURBINE ON A URAL I COMPUTER (VYPOCET KRITICKYCH OTACEK TURBOSOUSTROJI NA SAMOCINNEM POCITACI URAL I),

# Descriptive Note:

# Corporate Author:

## FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH

# Report Date:

## 1967-11-30

# Pagination or Media Count:

##
13.0

# Abstract:

## A method is described for calculating the critical speed of a system of rotors of a turbo-set on the URAL I computer. The calculation is based on Prohls difference method which has been modified for computer application. The method is applicable for a system of a maximum of 10 shafts represented as fields, each field divided into a maximum of twenty sections. The given dynamic problem is defined by a differential equation with four boundary conditions. The rigidity of bearings is considered as a function of the revolution of the shaft, expressed in the form of a third degree polynomial. A program is compiled for the floating point system, using an external magnetic memory. It was later established that the same calculation could have been done five times faster, i.e., in about three hours, by using the fixed point system, and in about one hour by using the URAL II computer. An example illustrating the theory is presented.

# Distribution Statement:

## APPROVED FOR PUBLIC RELEASE

#