Notes for Engineer (Hidden)

fecd11ef-9e9b-46c4-a2b7-6604a78b9a0f 2 4 5 false false 0 decimal

&[DATE] &[TIME] - &[FILENAME]

3 appVersion 0.99.7610

3 - appVersion 0.99.7610

Notes for Engineer (Hidden) dB Functions

Industrial Noise Series V: Room Acoustics & Noise Control

http://www.babcock.com/-/media/61c845c7f1ef4915b330b983c45d326a.ashx

Vectorize is now an option and works well :)
This causes several issues below that I do not understand :(#L.pvec ΣL.p 1010 #L.pvec dB / 10 /^vectorize sum 10 log * dB * :

Sum of equipment dB(typically Lp)
Logarathmic addition function #L.pvec ΣL.p 1010 #L.pvec dB / n el 10 /^n 1 #L.pvec cols sum 10 log * dB * :

dB Pressure will convert to power
reference to 20 micro-Pa L.P 10 p p.ref / (2^10 log * ≡

Fix #1: variable in lieu of function within a function #ΣL.p #dist.ref L.W #ΣL.p dB / 20 #dist.ref m / 10 log * + (dB * :

We can measure sound pressure.  Sound Power is calculated (here)
and does not change. Sound Power Function re: pico Watt #L.pvec #dist.ref L.W #L.pvec ΣL.p dB / 20 #dist.ref m / 10 log * + (dB * :

Fix #1: variable in lieu of function within a function
Sound Power does not change wrt distance. We then use it to back calculate the sound pressures wrt distance from source(s).
Sound Pressure Function re: 20 mPa #dist #b #L.W L.p #L.W dB / 10 #b 4 π * #dist (2^* / 10 log * vectorize + (dB * :

Sound Power does not change wrt distance. We then use it to back calculate
 the sound pressures wrt distance from source(s)
Sound Pressure Function re: 20 mPa #dist #b #L.pvec #dist.ref L.p #L.pvec #dist.ref L.W dB / 10 #b 4 π * #dist (2^* / 10 log * vectorize + (dB * :

Vector (add value at end)

Function to add value at end of vector #last #vector Vector.add2end n #vector rows 1 + : #vector n 1 el #last : #vector 31 line :

Introduction

]]>

xxxxx

]]>

Geometry directivity factor b 24831 mat :

Is there a way to build this into the function 
taken care of by double vector? Half sphere Quarter sphere Eighth sphere 31 sys

Given

]]>

Sound pressure level as measured by vendor
Note input is a vector for mult equip.
See Assumptions L.pvend 757721 mat dB * :

Distance as measured by vendor
Use meters! dist.vend 1.5 m * :

Project Specified dB dB.final 55 dB * :

Assumptions

]]>

The sound given by the vendor is assumed to be in dB(A) This needs to be confirmed by the engineer as the values are not transferable

]]>

Assumed Geometry directivity factor b.vend 2 :

Range to do the analysis.
This is in meters! x 1100 range m * :

This is additional ambient noise.  This is engineering assumption Amb.guess 78 dB * :

Solve

]]>

L.pvend Amb.guess L.pvend Vector.add2end (transpose : dB 75777813 mat

Logarithmic addition of the known dB's (Pressure) L.pvend ΣL.p 81.609 dB *

Sound power as calculated with respect to Logarithmic addition of the known dB's (Pressure) L.pvend ΣL.p dist.vend L.W 85.131 dB *

Distance at which we mathematically meet the project required sound value
Solve blocks do NOT like units, e.g. #dist, even if divide out L.p x 2 L.pvend ΣL.p dist.vend L.W L.p dB / dB.final dB / ≡ x 1100 solve x 4 L.pvend ΣL.p dist.vend L.W L.p dB / dB.final dB / ≡ x 1100 solve x 8 L.pvend ΣL.p dist.vend L.W L.p dB / dB.final dB / ≡ x 1100 solve 31 mat m * : ft 42.02 59.42 84.03 31 mat

x ft / x m / 2 L.pvend ΣL.p dist.vend L.W L.p dB / augment x ft / x m / 4 L.pvend ΣL.p dist.vend L.W L.p dB / augment x ft / x m / 8 L.pvend ΣL.p dist.vend L.W L.p dB / augment L.p 1 el ft / dB.final augment L.p 2 el ft / dB.final augment L.p 3 el ft / dB.final augment 6 1 sys

NEW DEFINITIONS

Variables #X,#Y required.
Brought from heat capacity worksheet #X #Y rangeindividual plot Clear count 1 #Y length range plot 1 count el #X #Y f : 11 line for plot 31 line :

L.W L.pvend ΣL.p dist.vend L.W : 85.1306 dB *

b rows 3

b 1 el 2

b 24831 mat

Smaller range for troubleshooting x 152 range m * :

"count" is added to the equation for the second "range" variable
so it can be used in the plotting function.
Must be unitless/all units cancel. x b f L.W dB / 10 b count el 4 π * x m / (2^* / 10 log * vectorize + :

from above. Brought down for visualization #dist #b #L.pvec #dist.ref L.p #L.pvec #dist.ref L.W dB / 10 #b 4 π * #dist (2^* / 10 log * vectorize + (dB * :

Same function as heat capacity worksheet. Why not working here? x ft / b rangeindividual #

Troubleshoot area below!

Function works if define "b" as scalar L.W dB / 1024 π * x m / (2^* / 10 log * vectorize + 77.1488 71.1282 67.6064 65.1076 63.1694 51 mat

From above for reference x m / 2 L.pvend ΣL.p dist.vend L.W L.p dB / 77.1488 71.1282 67.6064 65.1076 63.1694 51 mat

From above for reference x m / 4 L.pvend ΣL.p dist.vend L.W L.p dB / 80.1591 74.1385 70.6167 68.1179 66.1797 51 mat

Function works if define "b" as scalar L.W dB / 10 b 4 π * x m / (2^* / 10 log * vectorize + vectorize #