Local file copy is getting created in the Rails application code base

i'm using rails 3.2.22 and ruby 2.2.

i'm creating a text file and i want to send that for download using send_to. My code works as expected but every time i hit the action one local copy of the file is getting created in my application root folder. I dont want this and file should directly go to download folder. Am i doing anything wrong ??

  def save_trunk_logs
    data = ""
    file = "test.txt"
    trunk_logs = some data
    File.open(file, "w") do |aFile|
      aFile.write("Trunk Name : #{trunk_name}\n")
      aFile.write("*"*100)
      aFile.write("\n")
      aFile.write("Time Stamp"+"\t"+"Log Message\n")
      trunk_logs.each do |msg|
      text =format_log_messages msg
        data << "#{data}\n"
     end
  end
send_file file, :type => 'application/text; charset=UTF-8', :disposition => 'attachment'
end

Any help is appreciated.

Thanks in advance.